Optically active quaternary ammonium salt having axial asymmetry and process for producing a-amino acid and derivative thereof with the same

ABSTRACT

The present invention provides a compound of the following formula (I) below. This compound (I) can be produced by reacting a 2,2′-dimethylene bromide-1,1′-binaphthyl derivative, which can be produced by a relatively small number of processes, with an easily available secondary amine. This compound (I) is useful as a chiral phase-transfer catalyst.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Division of U.S. Pat. No. 7,928,224 filed on Jul.24, 2006, which is a U.S. National Phase entry of PCT InternationalApplication No. PCT/JP2005/001623 filed on Jan. 27, 2005, which claimsthe benefit and priority of Japanese applications 2004-023317 filed onJan. 30, 2004 and 2004-056659 filed on Mar. 1, 2004, all of which arehereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to an optically active quaternary ammoniumsalt having axial asymmetry and a method for producing the same. Thepresent invention further relates to a method for producing an opticallyactive α-amino acid and derivatives thereof, by using this opticallyactive quaternary ammonium salt having axial asymmetry as aphase-transfer catalyst.

BACKGROUND ART

α-Alkyl-α-amino acids represented by the formula H₂NCH(R)COOH are veryimportant naturally occurring amino acids. Most of the α-alkyl-α-aminoacids exist in animals, plants, microorganisms or the like in the L-formhaving a L-configuration at α position carbon, and the L-formconstitutes a polypeptide chain. On the other hand, the D-form exists inplants, fungi or microorganisms as a non-protein compound. Furthermore,α,α-dialkyl-α-amino acids represented by a formula H₂NC(R)(R′)COOH arecompounds that are recently gaining attention because of their uniquefunctions such as being stereochemically stable and being notsusceptible to enzymatic hydrolysis by protease when the compound isincorporated into a peptide. Regarding the above-described respects, seeBellier, B, et al., J. Med. Chem., vol. 40, p. 3947, 1997; and Mossel,E. et al., Tetrahedron Asymmetry, vol. 8, p. 1305, 1997. The compoundscan be used, for example, as peptides having an enhanced activity,effective enzyme inhibitors, and chiral building blocks for synthesizingcompounds having various biological activities. Such α,α-dialkyl-α-aminoacids have been examined to be prepared by catalystic asymmetricreaction, but at present, no effective method for preparing the same hasbeen found out.

For example, the significance of chiral phase-transfer catalysts, whichallow stereoselective alkylation of glycine derivatives, is increased inthe field of process chemistry because of its easy application. A largenumber of researches as to design of phase-transfer catalysts have beenconducted by using mainly cinchona alkaloid derivatives until now andseveral useful methods have been reported (e.g., see Shioiri, T. et al.,Stimulating Concepts in Chemistry, edited by Vogtle, F. et al.,WILEY-VCR: Weinheim, p. 123, 2000; and O'Donnell, M. J., AldrichimicaActa, vol. 34, p. 3, 2001). However, when such phase-transfer catalystsare used, various problems are caused such as use of a halogen-basedsolvent, a long time reaction, or the necessity of low temperatureconditions. In particular, for synthesizing α,α-dialkyl-α-amino acids asdescribed above, chiral phase-transfer catalysts derived from suchcinchona alkaloid are not very useful.

The present inventors have prepared an optically active quaternaryammonium salt having axial asymmetry, and clarified that it can be usedas a phase-transfer catalyst for synthesizing stereoselectively α-aminoacids as described above (see Japanese Laid-Open Patent Publication No.2001-48866; Japanese Laid-Open Patent Publication No. 2003-81976; andOoi, T. et al., J. Am. Chem. Soc., vol. 122, p. 5228, 2000). Forexample, a spiro-compound represented by the following formula is veryuseful for asymmetric double alkylation of glycine derivatives andasymmetric monoalkylation of α-alkyl-α-amino acid derivatives (e.g.,alanine derivatives):

(where PhF₃ represents 3,4,5-trifluorophenyl group). However, a largenumber of processes are required in order to prepare such spirocatalysts, and for example, when chiral binaphthol, which is easilyavailable, is used as the starting raw material, as many as elevenprocesses are required only to prepare the structural portion on theleft side of the catalyst. Thus, preparation takes time and labor, andresults in high cost, which are large drawbacks.

DISCLOSURE OF INVENTION

The purpose of the present invention is to provide a chiralphase-transfer catalyst having a simplified structure that can beproduced by a fewer number of processes.

The present invention provides a compound represented by the followingformula (I) below:

wherein R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶,and R^(6′) are groups independently selected from the group consistingof:

(i) a hydrogen atom;

(ii) —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atomor a C₁ to C₄ alkyl group);

(iii) a cyano group;

(iv) a nitro group;

(v) a carbamoyl group;

(vi) an N—(C₁ to C₄ alkyl)carbamoyl group;

(vii) an N,N-di(C₁ to C₄ alkyl)carbamoyl group;

(viii) —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may bebranched);

(ix) a C₁ to C₆ alkyl group that may be branched or form a cyclic group;

(x) a C₂ to C₆ alkenyl group that may be branched or form a cyclicgroup;

(xi) a C₂ to C₆ alkynyl group that may be branched or form a cyclicgroup;

(xii) an aralkyl group, wherein the aryl moiety of the aralkyl group maybe substituted with at least one group selected from the groupconsisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(xiii) a heteroaralkyl group having a heteroaryl moiety, wherein theheteroaryl moiety may be substituted with at least one group selectedfrom the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(xiv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched),

a halogen atom, and

—S(O)_(n)—R (where n is 0, 1 or 2, and R is a C₁ to C₄ alkyl group thatmay be branched);

or may be substituted with —O—(CH₂)_(m)—O— (where m is 1 or 2) atpositions 3 and 4 taken together; and

(xv) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

R⁷ and R⁹ are groups independently selected from the group consistingof:

(i) a hydrogen atom;

(ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclicgroup;

(iii) a C₂ to C₁₂ alkenyl group that may be branched or form a cyclicgroup;

(iv) a C₂ to C₁₂ alkynyl group that may be branched or form a cyclicgroup;

(v) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vi) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vii) —(CH₂)_(n)OCONR¹⁰R¹¹ (where R¹⁰ and R¹¹ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) a C₂ to C₆ alkenyl group that may be branched or form a        cyclic group;    -   (4) a C₂ to C₆ alkynyl group that may be branched or form a        cyclic group;    -   (5) an aralkyl group, wherein the aryl moiety of the aralkyl        group may be substituted with at least one group selected from        the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;    -   (6) a heteroaralkyl group having a heteroaryl moiety, wherein        the heteroaryl moiety may be substituted with at least one group        selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;    -   (7) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and    -   (8) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(viii) —(CH₂)_(n)CONR¹²R¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₄ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(ix) —(CH₂)_(n)NR¹²COR¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(x) —(CH₂)_(n)NR¹²R¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xi) —(CH₂)_(n)Y—OR¹² (where Y is a C₁ to C₄ divalent saturatedhydrocarbon group that may be branched, and R¹² is a group selected fromthe group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xiii) —(CH₂)_(n)—S—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xiv) —(CH₂)_(n)—SO—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₄ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12); and

(xv) —(CH₂)_(n)—SO₂—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12); or R⁷ and R⁸ are taken        together to form a divalent group selected from the group        consisting of: —(CH₂)_(m)— (where m is an integer from 2 to 8);

X⁻ is an anion selected from the group consisting of a halide anion,SCN⁻, HSO₄ ⁻ and HF₂ ⁻.

In one embodiment, R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵,R^(5′), R⁶, and R^(6′) of the compound represented by the formula (I)are groups independently selected from the group consisting of:

(i) a hydrogen atom;

(xiv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

-   -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a halogen atom, and    -   —S(O)_(n)—R (where n is 0, 1 or 2, and R is a C₁ to C₄ alkyl        group that may be branched);        or may be substituted with —O—(CH₂)_(m)—O— (where m is 1 or 2)        at positions 3 and 4 taken together; and

(xv) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

-   -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom.

In a further embodiment, R¹—, R^(1′), R², R^(2′), R³, R^(3′), R⁴,R^(4′), R⁵, R^(5′), R⁶, and R^(6′) of the compound represented by theformula (I) are groups independently selected from the group consistingof a hydrogen atom, a 3,4,5-trifluorophenyl group, a3,4,5-trichlorophenyl group, a 3,4-difluorophenyl group, a 3-nitrophenylgroup, a 3-cyanophenyl group, a benzothiophenyl-2-yl group, a3,5-difluorophenyl group, a 3-trifluoromethylphenyl group, a2,4-difluorophenyl group, a 3-methylsulfonylphenyl group, and a2,3-bis(trifluoromethyl)phenyl group.

In a further embodiment, the compound represented by the formula (I) isa compound represented by the following formula (I′):

(where R¹ and R^(1′) are groups independently selected from the groupconsisting of a hydrogen atom, a 3,4,5-trifluorophenyl group, a3,4,5-trichlorophenyl group, a 3,4-difluorophenyl group, a 3-nitrophenylgroup, a 3-cyanophenyl group, a benzothiophenyl-2-yl group, a3,5-difluorophenyl group, a 3-trifluoromethylphenyl group, a2,4-difluorophenyl group, a 3-methylsulfonylphenyl group, and a2,3-bis(trifluoromethyl)phenyl group, and R⁷, R⁸ and X⁻ are groupsindependently as defined in claim 1).

In one embodiment, R⁷ and R⁸ of the compound represented by the formula(I) are groups independently selected from the group consisting of:

(ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclicgroup; and

(xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom,    -   (2) a C₁ to C₄ alkyl group that may be branched,    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom, and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom,        and n is an integer of 1 to 12).

In another embodiment, R⁷ and R⁸ of the compound represented by theformula (I) are groups independently selected from the group consistingof a methyl group, an ethyl group, an n-butyl group, an isobutyl group,an n-decyl group, and a cyclohexyl group.

In a further embodiment, R⁷ and R⁸ of the compound represented by theformula (I) are the same.

In another embodiment, R⁷ and R⁸ of the compound represented by theformula (I) are taken together to form a divalent group selected fromthe group consisting of: —(CH₂)_(m)— (where m is an integer from 2 to8);

The present invention also provides a method for producing the compoundrepresented by the formula (I), the method comprises:

a step of reacting a compound represented by the following formula (II):

with a secondary amine represented by the following formula (III):

in an organic solvent in the presence of an acid scavenging agent,

wherein in the formula (II), R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴,R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are groups independently selectedfrom the group consisting of:

(i) a hydrogen atom;

(ii) —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atomor a C₁ to C₄ alkyl group);

(iii) a cyano group;

(iv) a nitro group;

(v) a carbamoyl group;

(vi) an N—(C₁ to C₄ alkyl)carbamoyl group;

(vii) an N,N-di(C₁ to C₄ alkyl)carbamoyl group;

(viii) —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may bebranched);

(ix) a C₁ to C₆ alkyl group that may be branched or form a cyclic group;

(x) a C₂ to C₆ alkenyl group that may be branched or form a cyclicgroup;

(xi) a C₂ to C₆ alkynyl group that may be branched or form a cyclicgroup;

(xii) an aralkyl group, wherein the aryl moiety of the aralkyl group maybe substituted with at least one group selected from the groupconsisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(xiii) a heteroaralkyl group having a heteroaryl moiety, wherein theheteroaryl moiety may be substituted with at least one group selectedfrom the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(xiv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched),

a halogen atom, and

—S(O)_(n)—R (where n is 0, 1 or 2, and R is a C₁ to C₄ alkyl group thatmay be branched);

or may be substituted with —O—(CH₂)_(m)—O— (where m is 1 or 2) atpositions 3 and 4 taken together; and

(xv) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom; and

Z is a halogen atom, and

in the formula (III), R⁷ and R⁸ are groups independently selected fromthe group consisting of:

(i) a hydrogen atom;

(ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclicgroup;

(iii) a C₂ to C₁₂ alkenyl group that may be branched or form a cyclicgroup;

(iv) a C₂ to C₁₂ alkynyl group that may be branched or form a cyclicgroup;

(v) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vi) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vii) —(CH₂)_(n)OCONR¹⁰R¹¹ (where R¹⁰ and R¹¹ are each independently agroup selected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) a C₂ to C₆ alkenyl group that may be branched or form a        cyclic group;    -   (4) a C₂ to C₆ alkynyl group that may be branched or form a        cyclic group;    -   (5) an aralkyl group, wherein the aryl moiety of the aralkyl        group may be substituted with at least one group selected from        the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;    -   (6) a heteroaralkyl group having a heteroaryl moiety, wherein        the heteroaryl moiety may be substituted with at least one group        selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;    -   (7) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and    -   (8) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(viii) —(CH₂)_(n)CONR¹²R¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(ix) —(CH₂)_(n)NR¹²COR¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(x) —(CH₂)_(n)NR¹²R¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xi) —(CH₂)_(n)Y—OR¹² (where Y is a C₁ to C₄ divalent saturatedhydrocarbon group that may be branched, and R¹² is a group selected fromthe group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xiii) —(CH₂)_(n)—S—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xiv) —(CH₂)_(n)—SO—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12); and

(xv) —(CH₂)_(n)—SO₂—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12); or R⁷ and R⁸ are taken        together to form a divalent group selected from the group        consisting of: —(CH₂)_(m)— (where m is an integer from 2 to 8);

In one embodiment, R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵,R^(5′), R⁶, and R^(6′) of the compound represented by the formula (II)are groups independently selected from the group consisting of:

(i) a hydrogen atom;

(xiv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

-   -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a halogen atom, and    -   —S(O)_(n)—R (where n is 0, 1 or 2, and R is a C₁ to C₄ alkyl        group that may be branched);        or may be substituted with —O—(CH₂)_(m)—O— (where m is 1 or 2)        at positions 3 and 4 taken together; and

(xv) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

-   -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom.

In a further embodiment, R¹, R^(1″), R², R^(2′), R³, R^(3′), R⁴, R^(4′),R⁵, R^(5′), R⁶, and R^(6′) of the compound represented by the formula(II) are groups independently selected from the group consisting of ahydrogen atom, a 3,4,5-trifluorophenyl group, a 3,4,5-trichlorophenylgroup, a 3,4-difluorophenyl group, a 3-nitrophenyl group, a3-cyanophenyl group, a benzothiophenyl-2-yl group, a 3,5-difluorophenylgroup, a 3-trifluoromethylphenyl group, a 2,4-difluorophenyl group, a3-methylsulfonylphenyl group, and a 2,3-bis(trifluoromethyl)phenylgroup.

In a further embodiment, the compound represented by the formula (II) isa compound represented by the following formula (II′):

(where R¹ and are groups independently selected from the groupconsisting of a hydrogen atom, a 3,4,5-trifluorophenyl group, a3,4,5-trichlorophenyl group, a 3,4-difluorophenyl group, a 3-nitrophenylgroup, a 3-cyanophenyl group, a benzothiophenyl-2-yl group, a3,5-difluorophenyl group, a 3-trifluoromethylphenyl group, a2,4-difluorophenyl group, a 3-methylsulfonylphenyl group, and a2,3-bis(trifluoromethyl)phenyl group, and R⁷, R⁸ and Z are groupsindependently as defined above).

In another embodiment, R⁷ and R⁸ of the secondary amine represented bythe formula (II) are groups independently selected from the groupconsisting of:

(ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclicgroup; and

(xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom,    -   (2) a C₁ to C₄ alkyl group that may be branched,    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom, and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom,        and n is an integer of 1 to 12.

In a further embodiment, R⁷ and R⁸ of the secondary amine represented bythe formula (II) are groups independently selected from the groupconsisting of a methyl group, an ethyl group, an n-butyl group, anisobutyl group, an n-decyl group, and a cyclohexyl group.

In a still further embodiment, R⁷ and R⁸ of the secondary aminerepresented by the formula (II) are the same.

In another embodiment, R⁷ and R⁸ of the secondary amine represented bythe formula (II) are taken together to form a divalent group selectedfrom the group consisting of: —(CH₂)_(m)— (where m is an integer from 2to 8);

The present invention further provides a method for stereoselectivelyproducing a compound represented by the formula (VI);

the method comprises:

alkylating a compound represented by the formula (IV)

with a compound of the formula (V):R¹⁸—W  (V)using a compound represented by the formula (I) that is pure withrespect to axis symmetry as a phase-transfer catalyst:

in a medium in the presence of an inorganic base,

wherein in the formula (I), R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴,R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are groups independently selectedfrom the group consisting of:

(i) a hydrogen atom;

(ii) —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atomor a C₁ to C₄ alkyl group);

(iii) a cyano group;

(iv) a nitro group;

(v) a carbamoyl group;

(vi) an N—(C₁ to C₄ alkyl)carbamoyl group;

(vii) an N,N-di(C₁ to C₄ alkyl)carbamoyl group;

(viii) —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may bebranched);

(ix) a C₁ to C₆ alkyl group that may be branched or form a cyclic group;

(x) a C₂ to C₆ alkenyl group that may be branched or form a cyclicgroup;

(xi) a C₂ to C₆ alkynyl group that may be branched or form a cyclicgroup;

(xii) an aralkyl group, wherein the aryl moiety of the aralkyl group maybe substituted with at least one group selected from the groupconsisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(xiii) a heteroaralkyl group having a heteroaryl moiety, wherein theheteroaryl moiety may be substituted with at least one group selectedfrom the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(xiv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched),

a halogen atom, and

—S(O)_(n)—R (where n is 0, 1 or 2, and R is a C₁ to C₄ alkyl group thatmay be branched);

or may be substituted with —O—(CH₂)_(m)—O— (where m is 1 or 2) atpositions 3 and 4 taken together; and

(xv) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom; and

R⁷ and R⁸ are each independently a monovalent organic group or are takentogether to form a divalent organic group,

X— is a halide anion,

in the formulae (IV) and (VI),

R¹⁴ and R¹⁵ are each independently

(i) a hydrogen atom; or

(ii) an aryl group that may be substituted with a C₁ to C₄ alkyl groupthat may be branched, a C₁ to C₅ alkoxy group that may be branched, or ahalogen atom;

with the proviso the case where both R¹⁴ and R¹⁵ are hydrogen atoms isexcluded,

R¹⁶ is a group selected from the group consisting of:

(i) a hydrogen atom;

(ii) a C₁ to C₁₀ alkyl group that may be branched or form a cyclicgroup;

(iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclicgroup;

(iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclicgroup;

(v) an aralkyl group, wherein the aryl group of the aralkyl group may besubstituted with at least one group selected from the group consistingof:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vi) a heteroaralkyl group having a heteroaryl moiety, wherein theheteroaryl moiety may be substituted with at least one group selectedfrom the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vii) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom; and

(viii) a heteroaryl group, wherein the heteroaryl group may besubstituted with at least one group selected from the group consistingof:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

R¹⁷ is a C₁ to C₈ alkyl group that may be branched or form a cyclicgroup),

in the formulae (V) and (VI),

R¹⁸ is a group selected from the group consisting of:

(i) a C₁ to C₁₀ alkyl group that may be branched or form a cyclic group;

(ii) a C₃ to C₉ alkyl group or substituted allyl group that may bebranched or form a cyclic group;

(iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclicgroup;

(iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclicgroup;

(v) an aralkyl group, wherein the aryl moiety of the aralkyl group maybe substituted with at least one group selected from the groupconsisting of;

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vi) a heteroaralkyl group having a heteroaryl moiety, wherein theheteroaryl moiety may be substituted with at least one group selectedfrom the group

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vii) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of;

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(viii) a heteroaryl group, wherein the heteroaryl group may besubstituted with at least one group selected from the group consistingof:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom; and

(ix) a C₃ to C₉ propargyl group or substituted propargyl group that maybe branched, and

in the formula (V),

W is a functional group having a leaving ability, and

in the formula (VI),

* shows a newly produced asymmetric center.

In one embodiment, R⁷ and R⁸ of the compound represented by the formula(I) are groups independently selected from the group consisting of:

(i) a C₁ to C₁₂ alkyl group that may be branched or form a cyclic groupand/or may be substituted with a halogen atom;

(ii) a C₂ to C₁₂ alkenyl group that may be branched or form a cyclicgroup and/or may be substituted with a halogen atom;

(iii) a C₂ to C₁₂ alkynyl group that may be branched or form a cyclicgroup and/or may be substituted with a halogen atom;

(iv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(v) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vi) —(CH₂)_(n)OCONR¹⁰R¹¹ (where R¹⁰ and R¹¹ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) a C₂ to C₆ alkenyl group that may be branched or form a        cyclic group;    -   (4) a C₂ to C₆ alkynyl group that may be branched or form a        cyclic group;    -   (5) an aralkyl group, wherein the aryl moiety of the aralkyl        group may be substituted with at least one group selected from        the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;    -   (6) a heteroaralkyl group having a heteroaryl moiety,        wherein the heteroaryl moiety may be substituted with at least        one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;    -   (7) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (8) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(vii) —(CH₂)_(n)CONR¹²R¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of: a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(viii) —(CH₂)_(n)NR¹²COR¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(ix) —(CH₂)_(n)NR¹²R¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(x) —(CH₂)_(n)Y—OR¹² (where Y is a C₁ to C₄ divalent saturatedhydrocarbon group that may be branched, and R¹² is a group selected fromthe group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xi) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xii) —(CH₂)_(n)—S—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12);

(xiii) —(CH₂)_(n)—SO—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12); and

(xiv) —(CH₂)_(n)—SO₂—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom; and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom;        and n is an integer from 1 to 12); or R⁷ and R⁸ are taken        together to form a divalent group selected from the group        consisting of: —(CH₂)_(m)— (where m is an integer from 2 to 8);

In one embodiment, R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵,R^(5′), R⁶, and R^(6′) of the compound represented by the formula (I)are groups independently selected from the group consisting of:

(i) a hydrogen atom;

(xiv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

-   -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a halogen atom, and    -   —S(O)_(n)—R (where n is 0, 1 or 2, and R is a C₁ to C₄ alkyl        group that may be branched);        or may be substituted with —O—(CH₂)_(m)—O— (where m is 1 or 2)        at positions 3 and 4 taken together; and

(xv) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

-   -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom.

In a further embodiment, R¹, R^(1″), R², R^(2′), R³, R^(3′), R⁴, R^(4′),R⁵, R^(5′), R⁶, and R^(6′) of the compound represented by the formula(I) are groups independently selected from the group consisting of ahydrogen atom, a 3,4,5-trifluorophenyl group, a 3,4,5-trichlorophenylgroup, a 3,4-difluorophenyl group, a 3-nitrophenyl group, a3-cyanophenyl group, a benzothiophenyl-2-yl group, a 3,5-difluorophenylgroup, a 3-trifluoromethylphenyl group, a 2,4-difluorophenyl group, a3-methylsulfonylphenyl group, and a 2,3-bis(trifluoromethyl)phenylgroup.

In a further embodiment, the compound represented by the formula (I) isa compound represented by the following formula (I′):

(where R¹ and R^(1′) are groups independently selected from the groupconsisting of a hydrogen atom, a 3,4,5-trifluorophenyl group, a3,4,5-trichlorophenyl group, a 3,4-difluorophenyl group, a 3-nitrophenylgroup, a 3-cyanophenyl group, a benzothiophenyl-2-yl group, a3,5-difluorophenyl group, a 3-trifluoromethylphenyl group, a2,4-difluorophenyl group, a 3-methylsulfonylphenyl group, and a2,3-bis(trifluoromethyl)phenyl group, and R⁷, R⁸ and X⁻ are groupsindependently as defined above).

In another embodiment, R⁷ and R⁸ of the compound represented by theformula (I) are groups independently selected from the group consistingof:

(ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclicgroup; and

(xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom,    -   (2) a C₁ to C₄ alkyl group that may be branched,    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom, and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom,        and n is an integer of 1 to 12.

In a further embodiment, R⁷ and R⁸ of the compound represented by theformula (I) are groups independently selected from the group consistingof a methyl group, an ethyl group, an n-butyl group, an isobutyl group,an n-decyl group, and a cyclohexyl group.

In a still further embodiment, R⁷ and R⁸ of the compound represented bythe formula (I) are the same.

In another embodiment, R⁷ and R⁹ of the compound represented by theformula (I) are taken together to form a divalent group selected fromthe group consisting of: —(CH₂)_(m)— (where m is an integer from 2 to8);

In one embodiment, the compound represented by the formula (I) is usedin a ratio of 0.001 mol % to 0.1 mol % per 1 mol of the compoundrepresented by the formula (IV).

In one embodiment, the compound represented by the formula (I) is usedin a ratio of 0.005 mol % to 0.05 mol % per 1 mol of the compoundrepresented by the formula (IV).

The present invention also provides a method for producing an opticallyactive α-amino acid, the method comprises:

hydrolyzing an imino group (R¹⁴R¹⁵C═N—) and an ester group (—CO₂R¹⁷) ofthe compound represented by the formula (VI) that is obtained by theabove method, under an acidic condition:

(where R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are the same groups as defined above).

The present invention also provides a method for producing an opticallyactive α-amino acid, the method comprises:

hydrolyzing an imino group (R¹⁴R¹⁵C═N—) of the compound represented bythe formula (VI) that is obtained by the above method, under an acidiccondition:

(where R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are the same groups as defined above),and

hydrolyzing an ester group (—CO₂R¹⁷) of the acid hydrolyzed productunder an acidic or basic condition.

The present invention also provides a method for producing an opticallyactive α-amino acid, the method comprises:

hydrolyzing an ester group (—CO₂R¹⁷) of the compound represented by theformula (VI) that is obtained by the above method, under a basiccondition:

(where R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are the same groups as defined above),and

hydrolyzing an imino group (R¹⁴R¹⁵C═N—) of the basic hydrolyzed productunder an acidic condition.

The present invention provides a chiral phase-transfer catalyst having amore simplified structure. This phase-transfer catalyst can be producedby a fewer number of processes than conventional compounds. Thus, thephase-transfer catalyst of the present invention that can be providedmore easily can be utilized for synthesizing, for example,α-alkyl-α-amino acid derivatives and α,α-dialkyl-α-amino acids.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the terms used in the present invention will be defined.

The phrase “C₁ to C_(n) alkyl group that may be branched or form acyclic group” (where n is an integer) includes any linear alkyl grouphaving 1 to n carbon atoms, any branched alkyl group having 3 to ncarbon atoms, and any cyclic alkyl group having 3 to n carbon atoms.Examples of linear alkyl groups having 1 to 6 carbon atoms includemethyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl. Examples ofbranched alkyl groups having 3 to 6 carbon atoms include isopropyl,isobutyl, tert-butyl, and isopentyl. Examples of cyclic alkyl groupshaving 3 to 6 carbon atoms include cyclobutyl, cyclopentyl, andcyclohexyl. Furthermore, when “C₁ to C₁₂ alkyl group that may bebranched or form a cyclic group and/or may be substituted with a halogenatom” is referred to, any linear alkyl group having 1 to 12 carbonatoms, any branched alkyl group having 3 to 12 carbon atoms, and anycyclic alkyl group having 3 to 12 carbon atoms are included, and ahydrogen atom at any position of these alkyl groups may be substitutedwith a halogen atom. Examples of such an alkyl group include n-heptyl,isoheptyl, n-octyl, isooctyl, n-decyl, and n-dodecyl.

In N—(C₁ to C₄ alkyl) carbamoyl groups and N,N-di(C₁ to C₄ alkyl)carbamoyl groups, “C₁ to C₄ alkyl group” means C₁ to C₄ linear alkylgroups or C₃ to C₄ branched alkyl groups.

The phrase “C₂ to C_(n) alkenyl group that may be branched or form acyclic group” (where n is an integer) includes any linear alkenyl groupshaving 2 to n carbon atoms, any branched alkenyl groups having 3 to ncarbon atoms, and any cyclic alkenyl groups having 3 to n carbon atoms.Examples of linear alkenyl groups having 2 to 6 carbon atoms includeethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 1-pentenyl,2-pentenyl, 3-pentenyl, 4-pentenyl, and 1-hexenyl. Examples of branchedalkenyl groups having 3 to 6 carbon atoms include isopropenyl,1-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-1-propenyl,2-methyl-2-propenyl, and 1-methyl-2-butenyl. Examples of cyclic alkenylgroups having 3 to 6 carbon atoms include cyclobutenyl, cyclopentenyl,and cyclohexenyl. Furthermore, when “C₂ to C₁₂ alkenyl group that may bebranched or form a cyclic group and/or may be substituted with a halogenatom” is referred to, any linear alkenyl groups having 2 to 12 carbonatoms, any branched alkenyl groups having 3 to 12 carbon atoms, and anycyclic alkenyl groups having 3 to 12 carbon atoms are included, and ahydrogen atom at any position of these alkenyl groups may be substitutedwith a halogen atom. Examples of such an alkenyl group include1-heptenyl, 2-heptenyl, 1-octenyl, 1-decenyl, and 1-dodecenyl.

The phrase “C₂ to C_(n) alkynyl group that may be branched or form acyclic group” (where n is an integer) includes any linear alkynyl groupshaving 2 to n carbon atoms, any branched alkynyl groups having 3 to ncarbon atoms, and any cyclic alkynyl groups having 3 to n carbon atoms.Examples of linear alkynyl groups having 2 to 6 carbon atoms includeethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, and1-hexynyl. Examples of branched alkynyl groups having 3 to 6 carbonatoms include 1-methyl-2-propynyl. Examples of cyclic alkynyl groupshaving 3 to 6 carbon atoms include cyclopropylethynyl, andcyclobutylethynyl. Furthermore, when “C₂ to C₁₂ alkynyl group that maybe branched or form a cyclic group and/or may be substituted with ahalogen atom” is referred to, any linear alkynyl groups having 1 to 12carbon atoms, any branched alkynyl groups having 3 to 12 carbon atoms,and any cyclic alkynyl groups having 3 to 12 carbon atoms are included,and a hydrogen atom at any position of these alkynyl groups may besubstituted with a halogen atom. Examples of such an alkynyl groupinclude 1-heptynyl, 1-octynyl, 1-decynyl, and 1-dodecynyl.

The phrase “C₁ to C_(n) alkoxy group that may be branched” (where n isan integer) includes alkoxy groups having any linear alkyl groups having1 to n carbon atoms and alkoxy groups having any branched alkyl groupshaving 3 to n carbon atoms. Examples thereof include methyloxy,ethyloxy, n-propyloxy, isopropyloxy, and tert-butyloxy.

Examples of “aralkyl group” in the present invention include benzyl,phenethyl, and naphthylmethyl.

Examples of “heteroaralkyl group” in the present invention includepyridylmethyl, indolylmethyl, furylmethyl, thienylmethyl, andpyrrolylmethyl.

Examples of “aryl group” in the present invention include phenyl,naphthyl, anthryl and phenanthryl.

Examples of “heteroaryl group” in the present invention include pyridyl,pyrrolyl, imidazolyl, furyl, indolyl, thienyl, oxazolyl,benzothiophenyl-2-yl, thiazolyl, 3,4-methylenedioxyphenyl,3,4-ethylenedioxyphenyl and tetrazolyl.

Examples of “halogen atom” in the present invention include a chlorineatom, a bromine atom, an iodine atom, and a fluorine atom. In thepresent invention, the term “halide anion” refers to halogen ions andexamples thereof include a chloride ion, a bromide ion, an iodide ionand a fluoride ion.

The phrase “C₃ to C_(n) alkyl group or substituted allyl group that maybe branched or form a cyclic group” (where n is an integer) refers toallyl groups or any substituted allyl groups having a substituent(s) atposition 1 and/or 2 and/or 3 and having 4 to n carbon atoms in total,and for example, includes 2-butenyl, 1-cyclopentenylmethyl, and3-methyl-2-butenyl.

The phrase “C₃ to C_(n) propargyl group or substituted propargyl groupthat may be branched” (where n is an integer) refers to propargyl groupsor any substituted propargyl groups having a substituent(s) at position1 and/or 3 and having 4 to n carbon atoms in total, and for example,includes 2-butynyl, and 3-trimethylsilyl-2-propynyl.

In the present invention, the term “functional group having a leavingability” means an atom or an atom group that leaves from a substrate ina substitution reaction or an elimination reaction, that is, a leavinggroup, and for example, includes a halogen atom, and a sulfonyloxygroup.

In the present specification, for convenience, the group consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom may be referred to as “group (Q)”.

Hereinafter, the present invention will be described more specifically.

A quaternary ammonium salt of the present invention is pure with respectto axial asymmetry, and is a compound represented by the followingformula (I):

(where R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁵,and R^(6′) are groups independently selected from the group consistingof:

(i) a hydrogen atom;

(ii) —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atomor a C₁ to C₄ alkyl group);

(iii) a cyano group;

(iv) a nitro group;

(v) a carbamoyl group;

(vi) an N—(C₁ to C₄ alkyl)carbamoyl group;

(vii) an N,N-di(C₁ to C₄ alkyl)carbamoyl group;

(viii) —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may bebranched);

(ix) a C₁ to C₆ alkyl group that may be branched or form a cyclic group;

(x) a C₂ to C₆ alkenyl group that may be branched or form a cyclicgroup;

(xi) a C₂ to C₆ alkynyl group that may be branched or form a cyclicgroup;

(xii) an aralkyl group, wherein the aryl moiety of the aralkyl group maybe substituted with at least one group selected from the group (Q)consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(xiii) a heteroaralkyl group having a heteroaryl moiety, wherein theheteroaryl moiety may be substituted with at least one group selectedfrom the group (Q);

(xiv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group (Q) or may be substituted with—O—(CH₂)_(m)—O—(where m is 1 or 2) at positions 3 and 4 that are takentogether; and

(xv) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group (Q);

R⁷ and R⁸ are each independently a monovalent organic group or takentogether to form a divalent organic group, and

X⁻ is a halide anion, SCN⁻, HSO₄ ⁻ or HF₂ ⁻). The compound representedby the formula (I) may have a configuration of either (S) or (R).

The compound represented by formula (I) above usefully functions as aphase-transfer catalyst for producing an optically active α-amino acidor derivative thereof, in particular, an α,α-dialkyl-α-amino acid orderivative thereof. More specifically, when the compound represented byformula (I) above is used as a phase-transfer catalyst to produce anoptically active α-amino acid or derivative thereof represented byformula (VI) by alkylating a compound represented by formula (IV) with acompound represented by formula (V), the ammonium moiety constituting acation of this compound:

contributes to the reactivity in the alkylation, and the binaphthylmoiety:

contributes to the stereoselectivity in the alkylation reaction.Therefore, in one embodiment, R⁷ and R⁸ in the compound represented byformula (I) are groups that can retain the reactivity and selectivityderived from the ammonium moiety and the binaphthyl moiety of thecation. (or does not inhibit the reactivity and selectivity). Forexample, they can be monovalent organic groups or divalent organicgroups that are more inactive than the ammonium moiety and thebinaphthyl moiety. In other words, R⁷ and R⁸ are not groups that arehighly reactive themselves (or itself), but groups that do not affectthe reaction in the production of the amino acid or derivative thereofthat is described later. Alternatively, in the formula (I) above, R⁷ andR⁸ are (monovalent organic) groups independently selected from the groupconsisting of:

(i) a C₁ to C₁₂ alkyl group that may be branched or form a cyclic groupand/or may be substituted with a halogen atom;

(ii) a C₂ to C₁₂ alkenyl group that may be branched or form a cyclicgroup and/or may be substituted with a halogen atom;

(iii) a C₂ to C₁₂ alkynyl group that may be branched or form a cyclicgroup and/or may be substituted with a halogen atom;

(iv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group (Q);

(v) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group (Q);

(vi) —(CH₂)_(n)OCONR¹⁰R¹¹ (where R¹⁰ and R¹¹ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) a C₂ to C₆ alkenyl group that may be branched or form a        cyclic group;    -   (4) a C₂ to C₆ alkynyl group that may be branched or form a        cyclic group;    -   (5) an aralkyl group, wherein the aryl moiety of the aralkyl        group may be substituted with at least one group selected from        the group (Q);    -   (6) a heteroaralkyl group having a heteroaryl moiety, wherein        the heteroaryl moiety may be substituted with at least one group        selected from the group (Q);    -   (7) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (8) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12);

(vii) —(CH₂)_(n)CONR¹²R¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12);

(viii) —(CH₂)_(n)NR¹²COR¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12);

(ix) —(CH₂)_(n)NR¹²R¹³ (where R¹² and R¹³ are groups independentlyselected from the group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12);

(x) —(CH₂)_(n)Y—OR¹² (where Y is a C₁ to C₄ divalent saturatedhydrocarbon group that may be branched, and R¹² is a group selected fromthe group consisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12);

(xi) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12);

(xii) —(CH₂)_(n)—S—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12);

(xiii) —(CH₂)_(n)—SO—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12); and

(xiv) —(CH₂)_(n)—SO₂—R¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom;    -   (2) a C₁ to C₄ alkyl group that may be branched;    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group (Q); and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group (Q),        and n is an integer from 1 to 12); or        R⁷ and R⁸ are taken together to form a (divalent organic) group        selected from the group consisting of: —(CH₂)_(m)— (where m is        an integer from 2 to 8);

In the present invention, in the formula (I) above, R¹, R^(1′), R²,R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) arepreferably groups independently selected from the group consisting of:

(i) a hydrogen atom;

(xiv) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group consisting of:

-   -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a halogen atom, and    -   —S(O)_(n)—R (where n is 0, 1 or 2, and R is a C₁ to C₄ alkyl        group that may be branched);        or may be substituted with —O—(CH₂)_(m)—O— (where m is 1 or 2)        at positions 3 and 4 taken together; and

(xv) a heteroaryl group, wherein the heteroaryl group may be substitutedwith at least one group selected from the group consisting of:

-   -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom,        more preferably, they are selected from the group consisting of        a hydrogen atom, a 3,4,5-trifluorophenyl group, a        3,4,5-trichlorophenyl group, a 3,4-difluorophenyl group, a        3-nitrophenyl group, a 3-cyanophenyl group, a        benzothiophenyl-2-yl group, a 3,5-difluorophenyl group, a        3-trifluoromethylphenyl group, a 2,4-difluorophenyl group, a        3-methylsulfonylphenyl group, and a        2,3-bis(trifluoromethyl)phenyl group. In particular, of the        compounds represented by the formula (I) above, a compound        represented by the following formula (I′) is preferable:

(where, R¹ and R^(1′) are groups selected independently from the groupconsisting of a hydrogen atom, a 3,4,5-trifluorophenyl group, a3,4,5-trichlorophenyl group, a 3,4-difluorophenyl group, a 3-nitrophenylgroup, a 3-cyanophenyl group, a benzothiophenyl-2-yl group, a3,5-difluorophenyl group, a 3-trifluoromethylphenyl group, a2,4-difluorophenyl group, a 3-methylsulfonylphenyl group, and a2,3-bis(trifluoromethyl)phenyl group, and R⁷, R⁸ and X⁻ are eachindependently the above-defined groups).

Furthermore, preferably, R⁷ and R⁸ of the compound represented by theformula (I) above are groups independently selected from the groupconsisting of:

(ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclicgroup; and

(xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the groupconsisting of:

-   -   (1) a hydrogen atom,    -   (2) a C₁ to C₄ alkyl group that may be branched,    -   (3) an aryl group, wherein the aryl group may be substituted        with at least one group selected from the group consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom, and    -   (4) a heteroaryl group, wherein the heteroaryl group may be        substituted with at least one group selected from the group        consisting of:    -   a C₁ to C₄ alkyl group that may be branched,    -   a C₁ to C₅ alkoxy group that may be branched,    -   an aryl group that may be substituted with a C₁ to C₄ alkyl        group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰        and R²¹ are each independently a hydrogen atom or a C₁ to C₄        alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄        alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group,        or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched),    -   a cyano group,    -   —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen        atom or a C₁ to C₄ alkyl group),    -   a nitro group,    -   a carbamoyl group,    -   an N—(C₁ to C₄ alkyl)carbamoyl group,    -   an N,N-di(C₁ to C₄ alkyl)carbamoyl group,    -   —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be        branched), and    -   a halogen atom, and n is an integer of 1 to 12, more preferably,        they are selected from the group consisting of a methyl group,        an ethyl group, an n-butyl group, an isobutyl group, an n-decyl        group, and a cyclohexyl group. Furthermore, R⁷ and R⁸ are        preferably the same, or a compound in which R⁷ and R⁸ are taken        together to form a divalent group selected from the group        consisting of: —(CH₂)_(m)— (where m is an integer from 2 to 8);

The quaternary ammonium salt represented by the formula (I) can beproduced by reacting a compound represented by the following formula(II):

(where R¹, R^(1′), R², R^(2′), R³, R^(2′), R⁴, R^(4′), R⁵, R^(5′), R⁶,and R^(6′) are the same as defined in the formula (I), and Z is ahalogen atom) with a secondary amine represented by the followingformula (III):

(where R⁷ and R⁸ are the same as defined in the formula (I)) in anorganic solvent in the presence of an acid scavenging agent.

The compound of the formula (II) can be prepared easily from, forexample, easily available 1,1′-binaphthyl-2,2′-dicarboxylic acid (seeSeki, M. et al., Synthesis, 2000, p. 1677) in a known process asdescribed in the following Scheme 1 (see Ooi, T. et al., J. Org. Chem.,vol. 68, p. 4577, 2003). The 1,1′-binaphthyl-2,2′-dicarboxylic acid maybe either the (S)-form or (R)-form.

The following is a more specific explanation based on Scheme 1 above.First, dicarboxylic acid (1) is converted to a correspondingdiisopropylester (2) using isopropyl bromide, a catalyst Bu₄N.HSO₄ andKF.2H₂O. The obtained compound (2) is treated with magnesiumbis(2,2,6,6-tetramethylpiperamide) (hereinafter, referred to asMg(TMP)₂), and then Br₂ is added thereto to give3,3′-dibromo-1,1′-dinaphthyl-2,2′-dicarboxylic acid ester (3). Then, theobtained compound (3) and 3,4,5-trifluorophenyl boronic acid aresubjected to the Suzuki-Miyaura cross-coupling reaction in the presenceof palladium acetate, triphenylphosphine and potassium carbonate to give3,3′-bis(3,4,5-trifluorophenyl)-1,1′-binaphthyl-2,2′-dicarboxylic acidester (4). Furthermore, this (4) is reduced with LiAlH₄ to obtainalcohol (5) and the obtained alcohol (5) is treated with PBr₃ so thatdibromide (6), which corresponds to the formula (II) above, can beobtained.

On the other hand, a large number of the secondary amines of the formula(III) above are commercially available, and therefore can be obtainedeasily, so that they can be selected as appropriate.

Examples of an organic solvent used in the process for producing thecompound of the formula (I) by reacting the compound of the formula (II)with the formula (III) include nitrile solvents (e.g., acetonitrile,propionitrile), ether solvents (e.g., dioxane, tetrahydrofuran,isopropyl ether, diethyl ether, dimethoxyethane, 2-methoxyethyl ether),alcohol solvents (methanol, ethanol, n-propanol, isopropanol, n-butanol,tert-butanol). In the present invention, acetonitrile is particularlypreferable. Examples of an acid scavenging agent include inorganic basessuch as potassium carbonate, sodium carbonate, potassiumhydrogencarbonate, sodium hydrogencarbonate).

In the reaction, the secondary amine of the formula (III) is preferablyused in 1 to 4 equivalents, more preferably 2 to 3 equivalents to thecompound of the formula (II). The acid scavenging agent is preferablyused in 1 to 4 equivalents, more preferably about 1 to 2 equivalents tothe compound of the formula (II). The compound of the formula (II) andthe secondary amine of the formula (III) are reacted with each other inthe presence of the acid scavenging agent in an appropriate organicsolvent with stirring. The reaction temperature is preferably from roomtemperature to the boiling point of the organic solvent, and morepreferably the reaction is performed under heating reflux. The reactiontime is preferably 30 minutes to 24 hours, more preferably 6 to 12hours. In this case, the organic solvent is preferably used 5 to 50times, more preferably 5 to 30 times the amount of the compound of theformula (II) in the ratio of volume (mL)/weight (g). After the reactionis finished, the reaction mixture is extracted with dichloromethane,dichloroethane, or carbon tetrachloride, and isolated and purified bysilica gel column chromatography, so that the compound of the formula(I) can be obtained. Alternatively, the reaction mixture may be used, asit is, as a phase-transfer catalyst in the method for producing α-aminoacid derivatives, which will be more specifically described later.

Thus obtained compound of the formula (I) in which X⁻ is a halide anionhas a pure form with respect to axial asymmetry, and can be used as aphase-transfer catalyst. Here, “pure with respect to axial asymmetry”means that among the stereoisomers based on axial asymmetry, the rate ofthe presence of one specific isomer is higher than that of otherisomers. Preferably, the rate of the presence of the one specific isomeris 90% or more, more preferably 95% or more, and even more preferably98% or more.

Furthermore, the compound of the formula (I) in which X⁻ is a halideanion can be made into a compound in which the halide anion is convertedto SCN⁻, HSO₄ ⁻ or HF₂ ⁻, for example, through the following process.

First, a method for producing the compound of the formula (I) in whichX⁻ is SCN⁻ or HSO₄ ⁻ will be described.

The compound of the formula (I) obtained in the above-described mannerin which X⁻ is a halide anion is dissolved in, for example, a suitablesecond organic solvent according to the method described in JapaneseLaid-Open Patent Publication No. 2002-173492 and mixed with a saturatedaqueous solution of an alkali metal salt of thiocyanic acid so that thehalide anion of X⁻ is converted to SCN⁻.

Examples of the second organic solvent that can be used for thisexchange include dichloromethane, chloroform, dichloroethane,tetrahydrofuran, methyl t-butyl ether, diisopropyl ether, and ethylacetate. Examples of the alkali metal salt of thiocyanic acid includepotassium thiocyanate and sodium thiocyanate.

For example, by mixing the compound of the formula (I) in which X⁻ is ahalide anion with an alkali metal salt of thiocyanic acid in a solutionunder a relatively mild condition such as under room temperature so asto come into contact, the reaction thereof can proceed easily, and thereaction product (e.g., the compound of the formula (I) in which X⁻ isSCN⁻) can be obtained in a quantitative yield.

Furthermore, by reacting the compound of the formula (I) in which X⁻ isSCN⁻ with a concentrated nitric acid solution, X⁻ can be convertedeasily from SCN⁻ to HSO₄ ⁻.

By further reacting thus obtained compound of the formula (I) in whichX⁻ is HSO₄ ⁻ with an alkali metal fluoride (e.g., potassium fluoride,sodium fluoride or lithium fluoride), a compound represented by theformula (Ia):

(where R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶,and R^(6′) are the same as defined in the formula (I)) can be obtained,which can be used as a catalyst, for example, in a reaction of a silylenol ether and a carbonyl compound (aldol reaction).

Examples of silyl enol ether used in the aldol reaction include atrialkylsilyl enol ether. A trialkylsilyl enol ether can be prepared inadvance by reacting a chlorosilane such as trimethylsilyl chloride andtriethylsilyl chloride with a carbonyl compound (e.g., ketonederivatives such as 2-butanone, 4-penten-2-one, diethyl ketone,acetophenone, propiophenone, butyronaphtone, cyclohexanone, 1-oxoindan,1-tetralone or 2-tetralone) in the presence of a base.

In addition to the carbonyl compound (the above-described ketonederivatives), which is a precursor of a silyl enol ether, examples ofthe carbonyl compound that can be reacted with a silyl enol ether usedin the aldol reaction, include aldehyde compounds such asacetylaldehyde, propionaldehyde, butylaldehyde, isobutylaldehyde,isovaleraldehyde, capronaldehyde, dodecylaldehyde, palmitinaldehyde,stearinaldehyde, acrolein, crotonaldehyde, cyclohexanecarbaldehyde,benzaldehyde, anisaldehyde, nicotinaldehyde, cinnamaldehyde,α-naphthaldehyde, and β-naphthaldehyde.

With respect to such a silyl enol ether and such a carbonyl compound,the compound represented by the formula (Ia) is used as a catalyst inthe aldol reaction so that the stereoselectivity in the reaction can becontrolled.

Next, a method for producing the compound of the formula (I) in which X⁻is HF₂ ⁻ will be described.

The compound of the formula (I) obtained in the above-described mannerin which X⁻ is a halide anion is first brought in contact with anion-exchange resin so that a first intermediate is produced.

As the ion-exchange resin, any ion-exchange resin can be selected bythose skilled in the art. Specific examples of the ion-exchange resinthat can be used include Amberlyst A26 (OH) (manufactured by ORGANOCORPORATION).

The compound of the formula (I) in which X⁻ is a halide anion can bebrought in contact with an ion-exchange resin by dissolving the compoundof the formula (I) in which X⁻ is a halide anion in a suitable thirdsolvent and passing this solution through a column filled with theion-exchange resin. As the third solvent that can be used for such acontact, alcohol solvents are preferable. Specific examples of alcoholsolvents include methyl alcohol, ethyl alcohol, isopropyl alcohol, andnormal propyl alcohol, although not limited thereto.

There is no limitation regarding the amounts of the compound of theformula (I) in which X⁻ is a halide anion and the third solvent that areused in this contact, and they can be set as appropriate by the thoseskilled in the art.

Thus, the first intermediate is produced.

Then, the obtained first intermediate is neutralized with a hydrogenfluoride aqueous solution preferably without removing the solvent.

There is no limitation regarding the amount of the hydrogen fluorideaqueous solution used in the present invention. In view of increasingthe productivity, preferably, the amount is selected so that hydrogenfluoride is reacted in an amount at least equivalent to that of thecompound of the formula (I) in which X⁻ is a halide anion. Thus, thefirst intermediate is neutralized, and a compound represented by theformula (Ib):

in which X⁻ is further converted from the halide anion to HF₂ ⁻ can beprecipitated in the solution.

Thereafter, the compound of this formula (Ib) can be easily isolated byremoving the solvent using means usually used by those skilled in theart.

Thus obtained compound of the formula (Ib) can be utilized as a catalystfor producing a nitroalcohol that is diastereoselectively andenantioselectively controlled.

Next, a method for producing α-amino acid derivatives using thequaternary ammonium compound of the present invention represented by theformula (I) as a phase-transfer catalyst will be described.

An α-amino acid derivative represented by the following formula (VI) canbe produced stereoselectively by a process for alkylating a compoundrepresented by the following formula (IV) with a compound of a formula(V), using the compound represented by the formula (I) as aphase-transfer in a medium in the presence of an inorganic base:

(where R¹⁴ and R¹⁵ are each independently

(i) a hydrogen atom; or

(ii) an aryl group that may be substituted with a C₁ to C₄ alkyl groupthat may be branched, a C₁ to C₅ alkoxy group that may be branched, or ahalogen atom; with the proviso that the case where both R¹⁴ and R¹⁵ arehydrogen atoms is excluded,

R¹⁶ is a group selected from the group consisting of:

(i) a hydrogen atom;

(ii) a C₁ to C₁₀ alkyl group that may be branched or form a cyclicgroup;

(iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclicgroup;

(iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclicgroup;

(v) an aralkyl group, wherein the aryl moiety of the aralkyl group maybe substituted with at least one group selected from the group (Q)consisting of:

a C₁ to C₄ alkyl group that may be branched,

a C₁ to C₅ alkoxy group that may be branched,

an aryl group that may be substituted with a C₁ to C₄ alkyl group thatmay be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are eachindependently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group,a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ toC₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl groupthat may be branched),

a cyano group,

—NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or aC₁ to C₄ alkyl group),

a nitro group,

a carbamoyl group,

an N—(C₁ to C₄ alkyl)carbamoyl group,

an N,N-di(C₁ to C₄ alkyl)carbamoyl group,

—NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and

a halogen atom;

(vi) a heteroaralkyl group having a heteroaryl moiety, wherein theheteroaryl moiety may be substituted with at least one group selectedfrom the group (Q);

(vii) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group (Q); and

(viii) a heteroaryl group, wherein the heteroaryl group may besubstituted with at least one group selected from the group (Q);

R¹⁷ is a C₁ to C₈ alkyl group that may be branched or form a cyclicgroup;

R¹⁸ is a group selected from the group consisting of:

(i) a C₁ to C₁₀ alkyl group that may be branched or form a cyclic group;

(ii) a C₃ to C₉ alkyl group or substituted allyl group that may bebranched or form a cyclic group;

(iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclicgroup;

(iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclicgroup;

(v) an aralkyl group, wherein the aryl moiety of the aralkyl group maybe substituted with at least one group selected from the group (Q);

(vi) a heteroaralkyl group having a heteroaryl moiety, wherein theheteroaryl moiety may be substituted with at least one group selectedfrom the group (Q);

(vii) an aryl group, wherein the aryl group may be substituted with atleast one group selected from the group (Q);

(viii) a heteroaryl group, wherein the heteroaryl group may besubstituted with at least one group selected from the group (Q); and

(ix) a C₃ to C₉ propargyl group or substituted propargyl group that maybe branched; and

* shows a newly generated asymmetric center;

(where R¹⁴, R¹⁵, R¹⁶ and R¹⁷ are the same as defined in the formula(VI)); andR¹⁸—W  (V)(where R¹⁸ is the same as defined in the formula (VI), and W is afunctional group having a leaving ability).

Examples of the medium used in this process include benzene, toluene,xylene, ethyl ether, isopropyl ether, tetrahydrofuran, and dioxane.Alternatively, the medium may be a two-phase medium containing water anda medium of these which is immiscible with water. The medium may be usedin a volume (mL)/weight (g) ratio of a factor, preferably of 5 to 30,more preferably 8 to 25 to the compound of the formula (IV).

Examples of the inorganic base used in this process include lithiumhydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide,rubidium hydroxide, and cesium hydroxide. The inorganic base may be usedpreferably in 2 to 10 equivalents, more preferably 3 to 7 equivalents tothe compound of the formula (IV). The inorganic base may be used in theform of a 10 to 60 w/v % alkali aqueous solution, and the volume in thiscase may be preferably a factor of 4 to 20, more preferably 8 to 15 involume (mL)/weight (g) ratio to the compound of the formula (IV).

In the alkylation process, the compound of the formula (V) is usedpreferably in 1 to 1.5 equivalents, more preferably 1.1 to 1.3equivalents, and even more preferably 1.2 to 1.25 equivalents to thecompound of the formula (IV). The compound of the formula (I) is used,as a phase-transfer catalyst, preferably in 0.001 mol % to 0.1 mol %,more preferably 0.005 mol % to 0.05 mol % to 1 mol of the compound ofthe formula (IV). Thus, the phase-transfer catalyst used in the presentinvention has a high activity, and therefore by using the catalyst atonly a small amount to 1 mole of the compound of the formula (IV), adesired optically active α-amino acid and derivatives thereof can beproduced.

In the present invention, in addition to such a phase-transfer catalyst,achiral quaternary ammonium salts such as tetrabutyl ammonium bromide(TBAB) may be also used in the reaction system simultaneously. Forexample, TBAB functions as a cocatalyst in the reaction system in thepresent invention to improve the yield of an α-amino acid and itsderivatives obtained, and also can further reduce the amount of thephase-transfer catalyst represented by the formula (I) used in thepresent invention. The amount of TBAB that can be used in the presentinvention is preferably 0.005 mol % to 0.1 mol %, and more preferably0.01 to 0.06 mol % to 1 mol of the compound of the formula (IV).

The alkylation process is performed at a suitable temperature between−30° C. to room temperature, preferably −20° C. to 0° C., in air,preferably in an argon atmosphere. This process is performed withstirring over a suitable period until an alkylation reaction proceeds toa sufficient extent. The reaction time is preferably 30 min to 48 hours,more preferably 1 hour to 24 hours.

According to the method of the present invention using the compound ofthe formula (I) of the present invention as described above, anoptically active compound of the formula (VI) can be obtained in a highyield and high optical purity. Here, “high optical purity” refers to atleast 80% ee, preferably at least 85% ee, more preferably 90% ee, andeven more preferably at least 95% ee.

In another aspect of the present invention, a method for producing anoptically active α-amino acid is provided.

In the present invention, an optically active α-amino acid can beproduced by performing, for example, either one of the followingprocedures, using the optically active compound of the formula (VI)(optically active α-amino acid derivative) that is obtained by theabove-described method.

In a first method, the imino group (R¹⁴R¹⁵C═N—) moiety of the opticallyactive compound of the formula (VI) (optically active α-amino acidderivative) that is obtained by the above-described method is hydrolyzedunder an acidic condition (imine acidic hydrolysis process). Examples ofthe acid used in the imine acidic hydrolysis process include inorganicacids (e.g., hydrochloric acid or phosphoric acid) and organic acidscontaining tribasic acid (e.g., acetic acid, citric acid). Morespecifically, the imine acidic hydrolysis process proceeds by treatingthe compound of the formula (VI) in a suitable medium (e.g.,tetrahydrofuran or toluene) at a suitable temperature (e.g., roomtemperature) using an aqueous solution of the acid as described above.As a result, an ester derivative of amino acid in which the terminalamino group is liberated can be obtained as an acidic hydrolysisproduct.

Then, the ester derivative of amino acid (acidic hydrolysis product)obtained by the above-described process is subjected to a hydrolysisreaction, if necessary, under acidic conditions stronger than the imineacidic hydrolysis or under basic conditions. Thus, a desired amino acidin which the terminal of the acidic hydrolysis product (i.e., an estergroup (—CO₂R¹⁷) in the acidic hydrolysis product) becomes carboxylicacid can be obtained.

Alternatively, in a second method, the process opposite to the methoddescribed above is adopted. That is to say, the ester group (—CO₂R¹⁷) inthe optically active compound of the formula (VI) (optically activeα-amino acid derivative) obtained in the above-described alkylationreaction is first hydrolyzed under basic conditions (ester basichydrolysis process). In this ester basic hydrolysis process, an alkaliaqueous solution such as sodium hydroxide aqueous solution can be used.By such hydrolysis, a basic hydrolysis product in which the terminal ofthe compound of the formula (VI) (i.e., an ester group (—CO₂R¹⁷) in thecompound of the formula (VI)) becomes carboxylic acid can be obtained.

Then, the imino group (R¹⁴R¹⁵C═N—) moiety of the above-obtained basichydrolysis product is hydrolyzed under an acidic condition (imine acidichydrolysis process). Examples of the acid used in the imine acidichydrolysis process include inorganic acids (e.g., hydrochloric acid,phosphoric acid, sulfuric acid) and organic acids including tribasicacid (e.g., acetic acid, citric acid). More specifically, the imineacidic hydrolysis process proceeds by treating the basis hydrolysisproduct in a suitable medium (e.g., tetrahydrofuran or toluene) at asuitable temperature (e.g., room temperature) using an aqueous solutionof the acid as described above. As a result, a desired amino acid inwhich the terminal amino acid is liberated can be obtained.

In the present invention, in the case where an amino acid is producedfrom the compound of the formula (VI), either the first method or thesecond method may be used, and either can be selected arbitrarily bythose skilled in the art, according to the specific structure of theamino acid to be actually produced and other production conditions.

In this manner, a desired optically active α-amino acid can be producedefficiently and optionally without limitations on its structure.

EXAMPLES

Hereinafter, the present invention will be more specifically describedby way of examples, but is not limited thereby.

In the following examples, ¹H NMR spectrum was measured on a JEOLJNM-FX400 (400 MHz) spectrometer and a JMTC-400/54/SS (400 MHz)spectrometer. The optical purity of a reaction product was measured byhigh-performance liquid chromatography (HPLC) with an apparatus Shimadzu10 using 4.6 mm×25 cm Daicel Chiralcel OD, OD-H, AD or AD-H. Thereaction progress was monitored with a Merck precoated TLC plate (silicagel 60 GF254, 0.25 mm) for thin film chromatography (TLC).

Reference Example 1 Synthesis of Starting Material (Compound 6) forSynthesizing Quaternary Ammonium Salt

A compound 1 (S-form), isopropyl bromide in 10 equivalents with respectto the compound 1, 20 mol % of a catalyst Bu₄N.HSO₄, and 10 equivalentsof potassium fluoride dihydrate were allowed to react for 24 hours underreflex in tetrahydrofuran to give a compound 2 in a 95% yield. Then, 4equivalents of Mg(TMP)₂ that was newly prepared in tetrahydrofuran wasadded dropwise to the compound 2 at 0° C., and subsequently 8equivalents of bromine was added dropwise at −78° C. Thereafter, thereaction mixture was stirred at room temperature for one hour to give acompound 3 in a 91% yield. The compound 3 and 2.4 equivalents of3,4,5-trifluorophenyl boronic acid were subjected to the Suzuki-Miyauracross-coupling reaction in the presence of 5 mol % of palladium acetate,15 mol % of PPh₃ and 3 equivalents of potassium carbonate indimethylformamide at 90° C. for 8 hours to give a compound 4 in a 94%yield. Then, the compound 4 was reduced with 3 equivalents of LiAlH₄ intetrahydrofuran at 0° C. to room temperature. Then, the obtainedcompound 5 was stirred with 0.5 equivalents of PBr₃ in tetrahydrofuranat 0° C. for one hour to give a compound 6 (S-form) in a 90% yield. TheR-form was prepared in the same manner.

Example 1 Synthesis of Quaternary Ammonium Salt (Compound 7)

A mixture of the compound 6 (S-form) (280 mg, 0.4 mmol), dibutylamine(140 μL, 0.8 mmol), and potassium carbonate (82 mg, 0.6 mmol) inacetonitrile (5 mL) was heated and refluxed for 10 hours with stirring.The mixture was poured into water and extracted with dichloromethane.The organic layer extract was dried over sodium sulfate, andconcentrated. The residue was purified by silica gel columnchromatography (eluent: methanol/dichloromethane=1:20) for purificationto give a compound 7 (S-form) (247 mg, 0.33 mmol) in a 83% yield.

The NMR spectrum of the obtained compound 7 (S-form) was as follows: ¹HNMR (400 MHz, CDCl₃) δ 7.97-7.95 (4H, m, Ar—H), 7.55-7.51 (2H, m, Ar—H),7.27-7.23 (8H m, Ar—H), 4.99 (2H, d, J=14.2 Hz, Ar—CH₂), 3.74 (2H, d,J=13.9 Hz, Ar—CH₂), 3.32 (2H, t, J=12.5 Hz, N—CH₂—CH₂), 2.56 (2H, t,J=12.31 Hz, N—CH₂—CH₂), 1.06-0.97 (6H, m, CH₂), 0.71 (6H, t, J=6.9 Hz,CH₃), 0.23 (2H, bs, CH₂); ¹³C NMR (100 MHz, CDCl₃) δ 150.95 (d,J_(C-F)=253 Hz), 139.61 (ddd, J_(C-F)=253, 15, 15 Hz), 138.31, 136.86,134.64 (d, J_(C-F)=4 Hz), 133.44, 131.13, 130.85, 128.31, 128.28,127.66, 127.37, 123.34, 115.31-113.76 (m), 57.58, 57.37, 24.60, 19.32,13.24.

For the R-form of the compound 6, the same procedure was performed togive the compound 7 (R-form).

Example 2 Confirmation of α-Benzylation Of Alanine

To a mixture of alanine (t)-butyl ester-p-chlorobenzyl Schiff base(compound 8) (134 mg, 0.5 mmol), 1 mol % of the compound 7 (S-form), andbenzyl bromide (1.2 equivalents) in 2 mL of toluene, cesiumhydroxide.monohydrate (5 equivalents) was added at 0° C., and stirredunder an argon atmosphere at 0° C. for 3 hours. The reaction mixture waspoured into water and extracted with dichloromethane, and the solventwas removed, and then the residue was dissolved in 5 mL oftetrahydrofuran. Then, 5 mL of 0.5 M citric acid aqueous solution wasadded thereto and the mixture was stirred at room temperature for onehour. The aqueous layer was washed with ether and alkalized with sodiumhydrogencarbonate, and then was extracted with dichloromethane. Theorganic layer was dried over sodium sulfate and concentrated to give anoily product. The obtained oily product was subjected to silica gelcolumn chromatography (eluent: ethyl acetate/hexane=2/1) to give abenzylated product of alanine (compound 9) in 97% ee and a 82% yield.The optical purity of the obtained product was analyzed by HPLC [DaicelChiralcel AD; eluent: hexane/isopropanol=30:1, 0.5 mL/min; retentiontime: (R)-form=12.9 min, (S)-form=20.5 min].

When the process under an argon atmosphere was performed at −20° C., acompound 9 having substantially complete enantioselectivity (99% ee) wasobtained in a 85% yield.

Example 3 Synthesis of Quaternary Ammonium Salt (Compound 10)

The same procedure as in Example 1 was performed except that the R-formof the compound 6 (140 mg, 0.2 mmol) was used and dicyclohexylamine wasused instead of dibutylamine. The product was purified by silica gelcolumn chromatography to give a compound 10 (R-form) (96 mg, 0.12 mmol)in a 60% yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CDCl₃) δ 8.05 (4H, bs, Ar—H), 7.65 (2H, t, J=7.7 Hz, Ar—H), 7.49(4H, bs, Ar—H), 7.38 (2H, t, J=7.5 Hz, Ar—H), 7.27-7.24 (2H, m, Ar—H),5.15 (2H, d, J=13.9 Hz, Ar—CH₂), 4.20 (2H, d, J=13.5 Hz, Ar—CH₂), 3.18(2H, bs, CH₂), 3.05 (1H, bs, N—CH), 2.34 (2H, d, J=9.9 Hz, CH₂), 2.16(2H, d, J=8.7 Hz, CH₂), 1.82-0.88 (15H, m, CH and CH₂); ¹³C NMR (100MHz, CDCl₃) δ 151.08 (d, J_(C-F)=249 Hz), 139.56 (d, J_(C-F)=254 Hz),138.43, 136.76, 134.80 (d, J_(C-F)=3.3 Hz), 133.34, 131.61, 131.05,128.33, 127.78, 127.44, 123.58, 115.05-114.82 (m), 73.95, 54.89, 53.37,52.99, 30.36, 28.69, 28.39, 26.62, 26.45, 24.88, 24.76.

Example 4 Synthesis of Quaternary Ammonium Salt (Compound 11)

The same procedure as in Example 1 was performed except that the R-formof the compound 6 (140 mg, 0.2 mmol) was used and1-aza-4,7,10,13-tetraoxacyclopentadecane was used instead ofdibutylamine. The product was purified by silica gel columnchromatography to give a compound 11 (59 mg, 0.07 mmol) in a 35% yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CDCl₃) δ 8.05-8.03 (4H, m, Ar—H), 7.68-7.64 (2H, m, Ar—H),7.43-7.35 (4H, m, Ar—H), 7.26-7.16 (4H, m, Ar—H), 4.89 (2H, d, J=13.9Hz, Ar—CH₂), 4.08 (2H, bs), 4.03 (2H, d, J=13.5 Hz, Ar—CH₂), 3.77-3.74(2H, m, CH₂), 3.58-3.54 (2H, m, CH₂), 3.50-3.45 (10H, m, CH₂), 3.38-3.35(2H, m, CH₂), 3.07-3.03 (2H, m, CH₂).

Example 5 Synthesis of Quaternary Ammonium Salt (Compound 12)

The same procedure as in Example 1 was performed except that the R-formof the compound 6 (140 mg, 0.2 mmol) was used and diethylamine was usedinstead of dibutylamine. The product was purified by silica gel columnchromatography to give a compound 12 (R-form) (120 mg, 0.17 mmol) in a87% yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CDCl₃) δ 8.02 (4H, bs, Ar—H), 7.67 (2H, t, J=7.5 Hz, Ar—H), 7.41(2H, t, J=7.7 Hz, Ar—H), 7.35-7.27 (6H, m, Ar—H), 5.04 (2H, d, J=13.9Hz, Ar—CH₂), 3.64 (2H, d, J=14.2 Hz, Ar—CH₂), 3.55-3.47 (2H, m,N—CH₂—CH₃), 2.73 (2H, q, J=6.9H, N—CH₂—CH₃), 0.64 (6H, t, J=6.9 Hz,CH₃).

Example 6 Synthesis of Quaternary Ammonium Salt (Compound 13)

The same procedure as in Example 1 was performed except that the R-formof the compound 6 (140 mg, 0.2 mmol) was used and1,2,3,4-tetrahydroisoquinoline was used instead of dibutylamine. Theproduct was purified by silica gel column chromatography to give acompound 13 (117 mg, 0.16 mmol) in a 78% yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CDCl₃) δ 8.08-8.02 (4H, m, Ar—H), 7.71-7.63 (2H, m, Ar—H),7.47-7.35 (4H, m, Ar—H), 7.26-7.14 (3H, m, Ar—H), 7.07 (2H, dd, J=7.5,7.5 Hz, Ar—H), 6.99 (2H, d, J=7.5 Hz, Ar—H), 6.63 (1H, d, J=7.5 Hz,Ar—H), 5.45 (1H, d, J=15.0 Hz, N—CH₂), 5.42 (1H, d, J=13.9 Hz, N—CH₂),4.83 (1H, d, J=12.7 Hz, N—CH₂), 4.12 (1H, d, J=13.9 Hz, N—CH₂),3.94-3.86 (2H, m, N—CH₂), 3.66 (1H, dd, J=11.7, 6.1 Hz), 3.36 (1H, dt,J=12.4, 5.3 Hz), 3.15-3.06 (1H, m), 2.83 (1H, dd, J=18.2, 4.7 Hz, CH₃).

Example 7 Synthesis of Quaternary Ammonium Salt (Compound 14)

The same procedure as in Example 1 was performed except that the S-formof the compound 6 (140 mg, 0.2 mmol) was used and dimethylamine was usedinstead of dibutylamine. The product was purified by silica gel columnchromatography to give a compound 14 (117 mg, 0.18 mmol) in a 88% yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CDCl₃) δ 8.03-8.01 (4H, m, Ar—H), 7.64 (2H, t, J=7.3 Hz, Ar—H),7.41-7.35 (4H, m, Ar—H), 7.12 (4H, bs, Ar—H), 4.92 (2H, d, J=13.5 Hz,Ar—CH₂), 3.76 (2H, d, J=13.9 Hz, Ar—CH₂), 2.96 (6H, s, N—CH₃).

Example 8 Synthesis of Quaternary Ammonium Salt (Compound 15)

The same procedure as in Example 1 was performed except that the S-formof the compound 6 (140 mg, 0.2 mmol) was used and diisobutylamine wasused instead of dibutylamine. The product was purified by silica gelcolumn chromatography to give a compound 15 (137 mg, 0.18 mmol) in a 91%yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CDCl₃) δ 8.00-7.96 (4H, m, Ar—H), 7.58-7.54 (2H, m, Ar—H),7.34-7.21 (8H, m, Ar—H), 4.54 (2H, d, J=13.1 Hz, Ar—CH₂), 4.11 (2H, d,J=13.4 Hz, Ar—CH₂), 3.08 (2H, dd, J=13.3, 4.9 Hz, N—CH ₂—CH), 2.39 (2H,dd, J=13.4, 4.9 Hz, N—CH ₂—CH), 2.00-1.93 (2H, m, CH), 0.86 (2H, d,J=6.3 Hz, CH₃), 0.76 (2H, d, J=6.7 Hz, CH₃).

Example 9 Synthesis of Quaternary Ammonium Salt (Compound 16)

The same procedure as in Example 1 was performed except that the S-formof the compound 6 (140 mg, 0.2 mmol) was used and di-n-decylamine wasused instead of dibutylamine. The product was purified by silica gelcolumn chromatography to give a compound 16 (117 mg, 0.13 mmol) in a 64%yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CDCl₃) δ 7.98-7.97 (4H, m, Ar—H), 7.57-7.53 (2H, m, Ar—H),7.32-7.27 (8H, m, Ar—H), 4.96 (2H, d, J=13.9 Hz, Ar—CH₂), 3.76 (2H, d,J=14.2 Hz, Ar—CH₂), 3.22 (2H, t, J=12.7 Hz, Ar—CH₂), 2.78 (1H, t, J=8.1Hz, Ar—CH₂), 2.60 (2H, t, J=11.1 Hz, CH₂), 1.80 (1H, bs), 1.29-0.85(34H, m), 0.34 (2H, m).

Reference Example 2 Synthesis of Starting Material (Compound 18) forSynthesizing Quaternary Ammonium Salt

To a mixture of a compound 17 (R-form) and pyridine in 4 equivalents tothe compound 17, 3 equivalents of trifluoromethane sulfonic acidanhydride (Tf₂O) in toluene was added dropwise over 40 min under anitrogen atmosphere at 2 to 9° C. with stirring. After the dropping ofTf₂O, the resulting mixture was stirred at room temperature for 3 hours.To this mixture, pyridine, water and 35% hydrochloric acid were added,then the organic layer was collected to give a trifurylated productquantitatively. Then, MeI (3 equivalents) was added dropwise to a Mg (3equivalents) solution in tert-butyl methyl ester (MTBE), and NiCl₂(dppp) (0.05 equivalents) was added thereto, and the trifurylatedproduct was further added dropwise thereto. The reaction mixture wasstirred at 55° C. under heating and reflux for 30 min, and toluene wasadded thereto. The resulting mixture was poured into cool water, andthen hydrochloric acid was added thereto. Thereafter, the organic layerwas collected to give a dimethylated product in a 96.1% yield. Then,N-bromosuccinimide (NBS; 2.5 equivalents) and2,2′-azobisisobutyronitrile (AIBN; 0.05 equivalents) were added to thedimethylated product in cyclohexane at room temperature, and thereaction mixture was heated and refluxed for 2 hours with stirring.After the mixture was cooled to room temperature, ethyl acetate wasadded thereto and the mixture was stirred and poured into water. Thetwo-layered mixture was stirred until no precipitate developed, and theprecipitate was collected to give a compound 18 (R-form) in a 54.3%yield.

Example 10 Synthesis of Quaternary Ammonium Salt (Compound 19)

The same procedure as in Example 1 was performed except that thecompound 18 (R-form) (88 mg, 0.2 mmol) was used and dicyclohexylaminewas used instead of dibutylamine. The product was purified by silica gelcolumn chromatography to give a compound 19 (54 mg, 0.10 mmol) in a 50%yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CDCl₃) δ 8.12 (2H, d, J=8.3 Hz, Ar—H), 8.02 (2H, d, J=8.7 Hz,Ar—H), 7.90 (2H, d, J=8.3 Hz, Ar—H), 7.59 (2H, dd, J=7.6, 8.3 Hz, Ar—H),7.42 (2H, d, J=8.7 Hz, Ar—H), 7.36 (2H, dd, J=7.6, 8.3 Hz, Ar—H), 5.40(2H, d, J=12.7 Hz, Ar—CH₂), 3.61 (2H, d, J=13.5 Hz, Ar—CH₂), 3.36 (2H,t, J=11.9 Hz, CH₂), 3.17 (2H, bs, CH₂), 3.03 (2H, d, J=10.3 Hz, CH₂),2.47 (2H, d, J=11.1 Hz, CH₂), 2.25-1.07 (14H, m).

Example 11 α-Benzylation by Various Phase-Transfer Catalysts

Glycine tert-butyl ester benzophenone Schiff base (compound 20) (14.8mg, 0.5 mmol), phase-transfer catalysts in amounts as described in Table1 below to the compound 20, 50% potassium hydroxide aqueous solution(1.0 mL), and toluene (3.0 mL) were mixed, and benzyl bromide (72.8 μg,0.5 mmol) was added dropwise thereto at 0° C. After each was stirred at0° C. for a period as described in Table 1 below, the reaction mixturewas poured into water, and extracted with ether. The ether extract waswashed with saturated brine, dried over sodium sulfate and concentratedunder reduced pressure. The oily residue was subjected to silica gelcolumn chromatography (eluted with ether/hexane= 1/10) to give(S)-phenylalanine tert-butyl ester benzophenone Schiff base (compound21). The optical purity of the obtained product was analyzed by HPLC[Daicel Chiralcel OD; eluent: hexane/2-propanol=100:1, 0.5 mL/min;retention time: (R)-form=14.8 min, (S)-form=28.2 min].

TABLE 1 Reaction Yield Optical purity Phase-transfer catalyst (amountused) time (hr) (%) (% ee)

48 14 5

20 94 87

48 14 89

21 86 97

32 80 85

54 63 14

36 80 1

48 20 98

48 18 97

7 days 11 6

Example 12 Examination of Effect of Temperature of α-Benzylation

According to Example 11, α-benzylation was performed at 0° C. or roomtemperature, using 3 mol % of a phase-transfer catalyst (compound 7 (R)or compound 16 (S)). The results are shown in Table 2.

TABLE 2 Reaction Optical time Yield purity Phase-transfer catalystReaction temperature (hr) (%) (% ee)

0° C. 21 86 97 room temperature  3 95 71

0° C. 48 18 97 room temperature  1 91 92

There is a tendency that when the temperature is high, the reaction timeis short and the yield is good, but the optical purity is good when thetemperature is low.

Reference Example 3 Synthesis of Starting Material (Compound 24 andCompound 25) for Synthesizing Quaternary Ammonium Salt

The compound 22 (S-form) and 4-methoxyphenyl boronic acid in 2equivalents to the compound 22 (S-form) were subjected to a Suzukicoupling reaction to give a compound 23 in a good yield. The compoundwas heated and refluxed together with 2.2 equivalents ofN-bromosuccinimide (NBS) and 0.1 equivalents of2,2′-azobisisobutyronitrile (AIBN) in benzene to give a compound 24 in agood yield. Then, the compound 24 was treated with 2.4 equivalents ofBBr₃ to give a compound 25 in a good yield. The R-form can be preparedin the same procedure.

Example 13 Synthesis of Quaternary Ammonium Salt (Compound 26)

The same procedure as in Example 1 was performed except that thecompound 24 (S-form) was used and di-n-decylamine was used instead ofdibutylamine. The product was purified by silica gel columnchromatography to give a compound 26 in a good yield.

Example 14 Synthesis of Quaternary Ammonium Salt (Compound 27)

The same procedure as in Example 1 was performed except that thecompound 25 (S-form) was used and di-n-decylamine was used instead ofdibutylamine. The product was purified by silica gel columnchromatography to give a compound 27 in a good yield.

The NMR spectrum of the obtained compound was as follows: ¹H NMR (400MHz, CD Cl₃) δ 8.04 (2H, s, Ar—H), 7.99 (2H, d, J=8.3 Hz, Ar—H),7.62-7.59 (2H, m, Ar—H), 7.37-7.22 (12H, m, Ar—H), 4.92 (2H, d, J=13.1Hz, Ar—CH₂), 3.43 (2H, d, J=13.1 Hz, Ar—CH₂), 3.17 (2H, brs, —CH₂—),2.74-2.68 (2H, m, —CH₂—), 1.25-0.82 (36H, m, —CH₂—, —CH₂—), 0.34 (2H,brs, —CH₂—).

Reference Example 4 Synthesis of Starting Material (Compound 29) forSynthesizing Quaternary Ammonium Salt

The compound 22 (S-form) and 3,5-di-tert-butylphenyl boronic acid in 2equivalents to the compound 22 were subjected to a Suzuki couplingreaction in barium hydroxide hexahydrate in 3 equivalents to thecompound 22, 5 mol % of palladium acetate and 1.2 mol % oftriphenylphosphine in water and dimethyl ether for 7 hours under reflux.The resulting mixture was cooled to room temperature, and a saturatedammonium chloride solution was added thereto, and the mixture wasextracted with ethyl ether to give a compound 28 in a 88% yield. Then,the compound 28 was refluxed together with 2 equivalents of NBS and 0.1equivalents of AIBN in benzene for one hour and concentrated, and thensubjected to silica gel column chromatography to give a compound 29 in a77% yield. The R-form can be prepared in the same procedure.

Example 15 Synthesis of Quaternary Ammonium Salt (Compound 30)

The same procedure as in Example 1 was performed except that thecompound 29 (S-form) was used and di-n-decylamine was used instead ofdibutylamine. The product was purified by silica gel columnchromatography to give a compound 30 in a good yield.

Reference Example 5 Synthesis (1) of Starting Material (Compound 32) forSynthesizing Quaternary Ammonium Salt

(where R″ is p-fluoro, m-fluoro, 3,4-difluoro, 3,4,5-trifluoro,p-chloro, m-chloro, 3,4,5-trichloro, 3,5-trifluoromethyl,3,5-di-tert-butyl, p-methoxy, p-trifluoromethoxy, p-hydroxy,3,5-diphenyl, p-(3,4,5-trifluorophenyl),p-(2,3,4,5,6-pentafluorophenyl), m-cyano, or m-nitro, and two R″ may bethe same or different).

The compound 22 (S-form) and an aryl boronic acid derivative in 2equivalents to the compound 22 were subjected to a Suzuki couplingreaction in 3 equivalents of potassium hydroxide or potassium phosphate,5 mol % of palladium acetate and 1.2 mol % of triphenylphosphine intetrahydrofuran for 7 hours under reflux. The resulting mixture wascooled to room temperature, and a saturated ammonium chloride solutionwas added thereto, and the mixture was extracted with ethyl ether togive a compound 31 in a 87% yield. Then, the compound 31 was refluxedwith 2 equivalents of N-bromosuccinimide and 0.1 equivalents of2,2′-azobisisobutyronitrile in benzene for one hour and concentrated,and then was subjected to silica gel column chromatography to give acompound 32 in a 97% yield. The R-form can be prepared in the sameprocedure.

Example 16 Synthesis (1) of Quaternary Ammonium Salt (Compound 33)

The same procedure as in Example 1 was performed except that thecompound 32 (S-form) was used and dibutylamine as used in Example 1 ordiamine R⁷—NH—R⁸ (where R⁷ and R⁸ are the same and are methyl, n-butyl,isobutyl, 1-hydroxyethyl, 1-methoxyethyl, n-decyl, cyclohexyl, or1-propynyl, or R⁷ and R⁸ are taken together to form:

was used instead of dibutylamine used in Example 1. The product waspurified by silica gel column chromatography to give a compound 33 in agood yield. The R-form can be prepared in the same procedure.

The structural formulae and the NMR spectrum data of the obtainedspecific compounds are shown in Tables 3 to 7.

TABLE 3

¹H NMR(400 MHz, CDCl₃) δ 8.05(2H, s, Ar—H), 8.02 (2H, d, J = 8.3 Hz,Ar—H), 7.63(2H, dd, J = 7.3, 7.3 Hz, Ar—H), 7.58(4H, brs, Ar—H),7.40-7.29(8H, m, Ar—H), 5.09(2H, d, J = 13.7 Hz, Ar—CH₃), 3.66(2H, d, J= 13.7 Hz, Ar—CH₂), 3.21(2H, t, J = 12.9 Hz, N—CH₂—CH₂—), 2.55 (2H, dt,J = 4.0, 12.9 Hz, N—CH₂—CH₂—), 1.01-0.98(4H, m, —CH₂—), 0.92-0.85(2H, m,—CH₂—), 0.67(6H, t, J = 6.9 Hz, —CH₃), 0.23-0.20(2H, m, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.03(2H, s, Ar—H), 8.00 (2H, d, J = 7.9 Hz,Ar—H), 7.61(2H, dd, J = 6.7, 6.7 Hz, Ar—H), 7.54(8H, brs, Ar—H),7.37-7.29(4H, m, Ar—H), 5.03(2H, d, J = 13.9 Hz, Ar—CH₃), 3.64(2H, d, J= 13.9 Hz, Ar—CH₂), 3.14(2H, t, J = 13.0 Hz, N—CH₂—CH₂—), 2.52 (2H, dt,J = 4.4, 13.0 Hz, N—CH₂—CH₂—), 0.98-0.96(4H, m, —CH₂—), 0.84-0.82(2H, m,—CH₂—), 0.65(6H, t, J = 6.9 Hz, —CH₃), 0.20-0.15(2H, m, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.02(2H, s, Ar—H), 7.98 (2H, d, J = 8.3 Hz,Ar—H), 7.60-7.57(4H, m, Ar—H), 7.35-7.28(8H, m, Ar—H), 7.12(2H, dd, J =8.3 Hz, Ar—H), 5.03(2H, br, N—CH₂—), 3.61(2H, d, J = 12.7 Hz, N—CH₂—),3.15(2H, br, N—CH₂—), 2.51(2H, brs, N—CH₂—), 0.95-0.89 (6H, m, —CH₂—),0.61(6H, t, J = 6.1 Hz, —CH₃), 0.13(2H, brs, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.03(2H, s, Ar—H), 8.00(2H, d, J = 7.9 Hz,Ar—H), 7.61(2H, dd, J = 7.3 Hz, Ar—H), 7.56(4H, brs, Ar—H), 7.43(2H, d,J = 7.5 Hz, Ar—H), 7.37-7.29(6H, m, Ar—H), 5.05(2H, brs, N—CH₂),3.60(2H, brs, N—CH₃), 3.19(2H, brs, N—CH₂—), 2.51(2H, brs, N—CH₂—),0.97-0.84(6H, m, —CH₂—), 0.65(6H, t, J = 6.7 Hz, —CH₃), 0.15(2H, brs,—CH₂—)

TABLE 4

¹H NMR(400 MHz, CDCl₃) δ 8.05(2H, s, Ar—H), 8.05 (2H, d, J =8.0 Hz,Ar—H), 7.73-7.63(5H, m, Ar—H), 7.42 (2H, dd, J = 8.3, 8.3 Hz, Ar—H),7.33(2H, d, J =8.3 Hz, Ar—H), 4.99(2H, d, J =13.9 Hz, Ar—CH₂), 3.78(2H,d, J = 13.9 Hz, Ar—CH₃), 3.34(2H, t, J = 13.5 Hz, N—CH₂—CH₂—), 2.67(2H,dt, J = 4.7, 13.1 Hz, N—CH₂—CH₂—), 1.13-1.11 (4H, m, —CH₂—),1.03-0.99(2H, m, —CH₂—), 0.73(6H, t, J = 7.5 Hz, —CH₃), 0.39-0.35(2H, m,—CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.06(2H, s, Ar—H), 8.03 (2H, d, J = 7.9 Hz,Ar—H), 7.66-7.62(6H, m, Ar—H), 7.45-7.32(8H, m, Ar—H), 5.07(2H, d, J =13.9 Hz, Ar—CH₂), 3.70(2H, d, J = 13.9 Hz, Ar—CH₂), 3.20(2H, t, J = 12.5Hz, N—CH₂—CH₂—), 2.57(2H, t, J = 12.9 Hz, N—CH₂—CH₂—), 0.98-0.95(4H, m,—CH₂—), 0.90-0.87(2H, m, —CH₂—), 0.65(6H, t, J = 6.9 Hz, —CH₃),0.25-0.21(2H, m, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.21(2H, s, Ar—H), 8.08 (2H, d, J = 8.3 Hz,Ar—H), 7.99(2H, s, Ar—H), 7.94(2H, s, Ar—H), 7.82-7.78(8H, m, Ar—H),7.69-7.62(4H, m, Ar—H), 7.53-7.33(16H, m, Ar—H), 5.15(2H, d, J = 13.7Hz, Ar—CH₂), 3.87(2H, d, J = 13.7 Hz, Ar—CH₂), 3.24(2H, t, J = 12.5 Hz,N—CH₂—CH₂—), 2.77(2H, dt, J = 4.4, 12.7 Hz, N—CH₂—CH₂—), 1.00-0.95(4H,m, —CH₂—), 0.82-0.78(2H, m, —CH₂—), 0.47-0.44(8H, m, —CH₂—, —CH₃)

¹H NMR(400 MHz, CDCl₄, 65° C.) δ 8.07-7.99(6H, m, Ar—H), 7.82-7.77(6H,m, Ar—H), 7.67(2H, dd, J = 7.7, 7.7 Hz, Ar—H), 7.41(2H, dd, J = 7.7, 7.7Hz, Ar—H), 7.33(2H, d, J = 7.9 Hz, Ar—H), 5.01(2H, brs, N—CH₂),3.76-3.74 (2H, m, N—CH₂—), 3.31(2H, br, N—CH₂), 2.56(2H, brs, N—CH₂—),1.05(4H, brs, —CH₂—), 0.93-0.92(2H, m, —CH₂—), 0.69(6H, t, J = 7.1 Hz,—CH₃), 0.24(2H, brs, —CH₂—)

TABLE 5

¹H NMR(400 MHz, CDCl₃) δ 8.22(2H, brs, Ar—H), 8.10-8.05(8H, m, Ar—H),7.73-7.69(2H, m, Ar—H), 7.48-7.44(2H, m, Ar—H), 7.40-7.38(2H, m, Ar—H),4.83 (2H, d, J = 14.3 Hz, Ar—CH₂), 4.03(2H, d, J = 14.3 Hz, Ar—CH₂),3.37(2H, t, J = 13.1 Hz, N—CH₂—CH₂—), 2.65 (2H, t, J = 12.9 Hz,N—CH₂—CH₂—), 1.10(4H, brs, —CH₂—), 0.87(2H, brs, —CH₂—), 0.63(6H, t, J =6.7 Hz, —CH₃), 0.32 (2H, brs, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.01(2H, s, Ar—H), 7.97(2H, d, J = 7.9 Hz,Ar—H), 7.60-7.56(2H, m, Ar—H), 7.46(4H, brs, Ar—H), 7.32-7.31(4H, m,Ar—H), 7.08(4H, d, J = 8.0 Hz, Ar—H), 5.05(2H, d, J = 13.5 Hz, Ar—CH₂),3.84(6H, s, —OCH₃), 3.57(2H, d, J = 13.5 Hz, Ar—CH₂), 3.03(2H, t, J =13.1 Hz, N—CH₂—CH₂—), 2.52(2H, dt, J = 4.0, 12.3 Hz, N—CH₂—CH₂—),0.94-0.87(6H, m, —CH₂—), 0.62(6H, t, J = 6.9 Hz, —CH₃), 0.21-0.17(2H,brs, —CH₂—)

¹H NMR(400 MHz, CDCl₃, 65° C.) δ 8.34(2H, s, Ar—H), 8.33(2H, d, J = 7.9Hz, Ar—H), 8.12(2H, s, Ar—H), 8.10-8.06(4H, m, Ar—H), 7.90(2H, dd, J =7.7, 7.7 Hz, Ar—H), 7.68(2H, dd, J = 7.1, 7.1 Hz, Ar—H), 7.43(2H, dd, J= 7.3, 7.3 Hz, Ar—H), 7.36(2H, d, J = 8.7 Hz, Ar—H), 5.05(2H, brs,N—CH₂—), 3.78(2H, d, J = 13.1 Hz, N—CH₂—), 3.35(2H, brs, N—CH₂—),2.56(2H, t, J = 12.7 Hz, N—CH₂—), 1.01-0.99(4H, m, —CH₂—), 0.82-0.80(2H,m, —CH₂—), 0.58(6H, t, J = 7.5 Hz, —CH₃), 0.22(2H, brs, —CH₂—)

¹H NMR(400 MHz, CDCl₃, 65° C.) δ 8.37(1H, s, Ar—H), 8.32(1H, d, J = 8.3Hz, Ar—H), 8.24(1H, d, J = 7.5 Hz, Ar—H), 8.12(1H,s, Ar—H),8.08-7.96(4H, m, Ar—H), 7.68-7.61(2H, m, Ar—H), 7.43-7.30(6H, m, Ar—H),7.09(2H, d, J = 7.9 Hz, Ar—H), 5.26(1H, brs, N—CH₂—), 4.96(1H, d, J =12.3 Hz, N—CH₂—), 3.88(3H, s, —OCH₃), 3.78(1H, d, J = 13.9 Hz, N—CH₂—),3.59(2H, d, J = 12.3 Hz, N—CH₂—), 2.82-2.78(1H, m, N—CH₂—), 2.57(2H,brs, N—CH₂—), 1.08(2H, brs, —CH₂—), 0.93(4H, brs, —CH₂—), 0.66(3H, t, J= 6.1 Hz, —CH₃), 0.58(3H, t, J = 7.2 Hz, —CH₃), 0.32-0.24(2H, m, —CH₂—)

TABLE 6

¹H NMR(400 MHz, CD₃OD) δ 8.12(2H, s, Ar—H), 8.09 (2H, d, J = 8.3 Hz,Ar—H), 7.64-7.60(2H, m, Ar—H), 7.51-7.22(8H, m, Ar—H), 6.96(4H, brs,Ar—H), 4.86(2H, d, J = 13.5 Hz, Ar—CH₂), 3.58(2H, d, J = 13.5 Hz,Ar—CH₂), 2.74(2H, t, J = 12.7 Hz, N—CH₂—CH₂—), 2.55 (2H, brs,N—CH₂—CH₂—), 1.00-0.95(6H, m, —CH₂—), 0.71 (6H, t, J = 6.3 Hz, —CH₃),0.23(2H, brs, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.09(2H, s, Ar—H), 8.06 (2H, d, J = 8.3 Hz,Ar—H), 7.66-7.62(2H, m, Ar—H), 7.57 (2H, s, Ar—H), 7.47(2H, s, Ar—H),7.42-7.37(4H, m, Ar—H), 7.21(2H, s, Ar—H), 5.09(2H, d, J = 13.5 Hz,Ar—CH₂), 3.79(2H, d, J = 13.5 Hz, Ar—CH₂), 3.16(2H, t, J = 13.1 Hz,N—CH₂—CH₂—), 2.52(2H, t, J = 6.0, 13.3 Hz, N—CH₂—CH₂—), 1.42(18H, s,—CH₃), 1.37(18H, s, —CH₃), 1.05-1.02(4H, brs, —CH₂—), 0.84-0.82(2H, brs,—CH₂—), 0.62(6H, t, J = 6.9 Hz, —CH₃), 0.53-0.49(2H, brs, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.12(2H, s, Ar—H), 8.05 (2H, d, J = 8.3 Hz,Ar—H), 7.74-7.64(10H, m, Ar—H), 7.42-7.36(4H, m, Ar—H), 7.30-7.26(4H, m,Ar—H), 5.20 (2H, d, J = 13.7 Hz, Ar—CH₂), 3.68(2H, d, J = 13.7 Hz,Ar—CH₂), 3.26(2H, t, J = 12.7 Hz, N—CH₂—CH₂—), 2.56 (2H, dt, J = 4.0,12.7 Hz, N—CH₂—CH₂—), 0.98-0.96(4H, m, —CH₂—), 0.87-0.82(2H, m, —CH₂—),0.53(6H, t, J = 6.9 Hz, —CH₃), 0.26-0.23(2H, m, —CH₂—)

TABLE 7

¹H NMR(400 MHz, CDCl₃) δ 8.15(2H, s, Ar—H), 8.07 (2H, d, J = 7.9 Hz,Ar—H), 7.76(4H, brs, Ar—H), 7.70-7.65 (6H, m, Ar—H), 7.44-7.33(4H, m,Ar—H), 5.21(2H, d, J = 13.7 Hz, Ar—CH₂), 3.75(2H, d, J = 13.7 Hz,Ar—CH₂), 3.29 (2H, t, J = 12.7 Hz, N—CH₂—CH₂—), 2.66-2.59(2H, m,N—CH₂—CH₂—), 1.01-0.95(6H, m, —CH₂—), 0.62(6H, t, J = 6.7 Hz, —CH₃),0.38(2H, brs, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 7.98-7.96(4H, m, Ar—H), 7.60-7.56(2H, m, Ar—H),7.34(4H, brs, Ar—H), 7.26(4H, br, Ar—H), 7.11(2H, dd, J = 7.7, 7.7 Hz,Ar—H), 6.82(1H, dd, J = 7.5, 7.5 Hz, Ar—H), 6.59(2H, d, J = 7.9 Hz,Ar—H), 4.92(2H, d, J = 13.7 Hz, Ar—CH₂—), 3.97(2H, d, J = 13.7 Hz,Ar—CH₂—), 3.84-3.79(2H, m, —CH₂—), 3.14-3.09(2H, m, —CH₂—),2.99-2.95(2H, m, —CH₂—), 2.54-2.49(2H, m, —CH₂—)

¹H NMR(400 MHz, CDCl₃) δ 8.05(2H, s, Ar—H), 8.03 (2H, d, J = 8.3 Hz,Ar—H), 7.64(2H, dd, J = 7.5, 7.5 Hz, Ar—H), 7.41-7.33(4H, m, Ar—H),7.26(4H, br, Ar—H), 4.99 (2H, d, J = 13.5 Hz, Ar—CH₂), 4.01(2H, d, J =13.5 Hz, Ar—CH₂), 3.57-3.54(6H, m, —CH₂—), 3.11(6H, s, —OCH₃), 3.07(2H,d, J = 9.2 Hz, —CH₂—)

Reference Example 6 Synthesis (2) of Starting Material (Compound 32′)for Synthesizing Quaternary Ammonium Salt

and the two R′″ may be the same or different).

The compound 22 (S-form) and an aryl boronic acid derivative in 2equivalents to the compound 22 were subjected to a Suzuki couplingreaction in 3 equivalents of potassium hydroxide or potassium phosphate,mol % of palladium acetate and 1.2 mol % of triphenylphosphine intetrahydrofuran for 7 hours under reflux. The resulting mixture wascooled to room temperature, and a saturated ammonium chloride solutionwas added thereto, and the mixture was extracted with ethyl ether togive compounds 31′ in yields below. Then, the compound 31 was refluxedwith 2 equivalents of N-bromosuccinimide and 0.1 equivalents of2,2′-azobisisobutyronitrile in benzene for one hour and concentrated,and then was purified by silica gel column chromatography to givecompounds 32′ in yields below. The specific structural formulae, theyields and the NMR spectrum data of the obtained compounds 31′ and 32′are shown in Tables 8 to 15. The R-form can be prepared in the sameprocedure.

TABLE 8 Compound 31′ Yield and NMR spectrum data

Yield: 74%, ¹H NMR(400 MHz, CDCl₃) δ 2.03(s, 6H): 7.14 (d, J = 8.4 Hz,2H); 7.25-7.27(m, 2H); 7.37-7.50(m, 8H); 7.57(d, J = 8.0 Hz, 8H);7.70(tr, J = 8.0 Hz, 2H); 7.91(d, J = 10.0 Hz, 4H).

Yield: 74%, ¹H NMR(400 MHz, CDCl₃) δ 1.94(s, 6H); 7.11 (d, J = 8.8 Hz,2H); 7.29-7.32(m, 2H); 7.48(tr, J = 7.2 Hz, 2H); 7.67(dd, J = 7.2 Hz,1.6 Hz, 2H); 7.86(s, 2H); 7.93(d, J = 8.0 Hz, 2H); 8.33(dd, J = 7.2 Hz,1.6 Hz, 2H),).

Yield: 72.5%, ¹H NMR(400 MHz, CDCl₃) δ 1.92(s, 6H); 7.09(d, 2H, J = 8.8Hz); 7.29(tr, 2H, J = 8.0 Hz); 7.47(tr, J = 7.6 Hz, 2H); 7.60(d, J = 8.0Hz, 2H); 7.77(d, J = 8.0 Hz, 2H); 7.83(s, 2H); 7.91(d, J = 8.4 Hz,2H),).

Yield: 77%, ¹H NMR(400 MHz, CDCl₃) δ 1.94(s, 6H); 6.02(s, 4H);6.83-6.98(m, 6H); 7.07(d, J = 8.4 Hz, 2H); 7.20-7.25(m, 2H); 7.41(tr, J= 7.6 Hz, 2H); 7.81(s, 2H); 7.87(d, J = 8.4 Hz, 2H).

TABLE 9 Compound 31′ Yield and NMR spectrum data

Yield: 69%, ¹H NMR(400 MHz, CDCl₃) δ 1.92(s, 6H); 7.07(d, J = 8.4 Hz,2H); 7.27-7.33(m, 4H); 7.45(tr, J = 7.6 Hz, 2H); 7.53(d, J = 8.4 Hz,2H); 7.58(d, J = 2.0 Hz, 2H); 7.61(s, 2H); 7.89(d, J = 8.0 Hz, 2H).

Yield: 73%, ¹H NMR(400 MHz, CDCl₃) δ 2.16(s, 6H); 7.11(d, J = 8.4 Hz,2H); 7.27-7.29(m, 2H); 7.34-7.47(m, 8H); 7.83(dd, J = 7.0 Hz, 0.8 Hz,2H); 7.88-7.93(m, 4H); 8.18(s, 2H).

Yield: 93%, ¹H NMR(400 MHz, CDCl₃) δ 1.94(s, 6H); 6.83-6.88(m, 2H),);7.00-7.05(m, 4H); 7.08(d, J = 8.4 Hz, 2H); 7.26-7.31(m, 2H);7.44-7.48(m, 2H); 7.84 (s, 2H); 7.91(d, J = 8.4 Hz, 2H),).

Yield: 60%, ¹H NMR(400 MHz, CDCl₃) δ 1.95(s, 6H); 3.87(s, 6H,);6.91-6.94(m, 2H); 7.02-7.11(m, 6H); 7.21-7.25(m, 2H); 7.35-7.43(m, 4H);7.84-7.89(m, 4H).

TABLE 10 Compound 31′ Yield and NMR spectrum data

Yield: 91%, ¹H NMR(400 MHz, CDCl₃): δ 1.94(s, 6H); 7.11(d, J = 8.4 Hz,2H); 7.26-7.31(m, 2H); 7.44-7.48 (m, 2H); 7.58(d, J = 8.0 Hz, 2H);7.64-7.68(m, 4H); 7.76(s, 2H); 7.86(s, 2H); 7.91(tr, J = 8.4 Hz, 2H).

Yield: 81%, ¹H NMR(400 MHz, CDCl₃): δ 1.94(s, 6H); 7.11(d, J = 8.8 Hz,2H); 7.26-7.32(m, 2H); 7.43-7.45(m, 2H); 7.59(d, J = 8.4 Hz, 4H);7.71(d, J = 8.4 Hz, 4H); 7.83(s, 2H); 7.89(d, J = 8.0 Hz, 2H).

Yield: 83%, ¹H NMR(400 MHz, CDCl₃): δ 1.86(s, 6H); 6.90-7.02(m, 4H);7.10-7.13(m, 2H); 7.27(d, J = 8.0 Hz, 2H); 7.43(tr, J = 8.0 Hz, 4H);7.83(s, 2H); 7.89(d, J = 8.0 Hz, 2H).

Yield: 61%, ¹H NMR(400 MHz, CDCl₃): δ 1.94(s, 6H); 3.15(s, 6H); 7.11(d,J = 8.4 Hz, 2H); 7.30(tr, J = 7.6 Hz, 2H); 7.47(tr, J = 7.6 Hz, 2H);7.70(d, J = 8.0 Hz, 4H); 7.85(s, 2H); 7.92(d, J = 8.0 Hz, 4H); 8.05(d, J= 8.0 Hz, 4H).

TABLE 11 Compound 31′ Yield and NMR spectrum data

Yield: 42%, ¹H NMR(400 MHz, CDCl₃) δ 1.94 (s, 6H); 6.88-6.91(m, 2H);6.88-6.91(m, 2H); 7.08(d, J = 4.2 Hz, 4H); 7.16(d, J = 8.4 Hz, 2H);7.32(tr, J = 7.6 Hz, 2H); 7.37(s, 8H); 7.50(tr, J = 7.6 Hz, 2H); 7.90(s,2H); 7.95(d, J = 8.4 Hz, 2H).

Yield: 70%, ¹ H NMR(400 MHz, CDCl₃) δ 2.02 (s, 6H); 7.19(d, J = 8.8 Hz,2H); 7.27-7.31(m, 2H); 7.43-7.47(m, 2H); 7.50-7.54(m, 4H); 7.62 (dd, J =8.4 Hz, 2.0 Hz); 7.90-7.97(m, 4H).

Yield: 83%, ¹H NMR(400 MHz, CDCl₃) δ 1.92 (s, 6H); 7.16-7.20(m, 4H);7.26-7.28(m, 4H); 7.32-7.49(m, 6H); 7.88(s, 2H), 7.91(d, J = 8.0 Hz,2H).

Yield: 73%, ¹H NMR(400 MHz, CDCl₃) δ 2.05 (s, 6H); 7.18(d, J = 8.4 Hz,2H); 7.31-7.35(m, 4H); 7.47-7.51(m, 2H); 7.77(dd, J = 4.4 Hz, 1.6 Hz,4H); 7.93(s, 4H); 7.95(s, 2H); 7.97(s, 2H); 8.11(s, 8H).

TABLE 12 Compound 32′ Yield and NMR spectrum data

Yield: 86% , ¹H NMR(400 MHz, CDCl₃) δ 4.36(s, 4H); 7.30(d, J = 8.0 Hz,2H); 7.32(tr, J = 8.0 Hz, 2H); 7.38(tr, J = 8.0 Hz, 2H); 7.48-7.55(m,6H); 7.69-7.76(m, 12H); 7.95(tr, J = 8.0 Hz, 4H).

Yield: 81%, ¹H NMR(400 MHz, CDCl₃) δ 2.04(s, 6H); 4.20(s, 4H); 7.17(d, J= 8.0 Hz, 2H); 7.35-7.36(m, 2H); 7.58(tr, J = 4.0 Hz, 2H); 7.81(dd, J =6.8 Hz, 1.6 Hz, 4H); 7.93(s, 2H); 7.96(d, J = 8.0 Hz, 2H); 8.37(d, J =8.0 Hz, 4H).

Yield: 84%, ¹H NMR(400 MHz, CDCl₃) δ 4.18(s, 4H); 7.15(d, J = 8.8 Hz,2H); 7.32-7.36(m, 2H); 7.56(tr, J = 8.8 Hz, 2H); 7.74(d, J = 8.0 Hz,4H); 7.80(d, J = 8.0 Hz, 4H); 7.89(s, 2H); 7.94(d, J = 8.0 Hz, 2H).

Yield: 71%, ¹H NMR(400 MHz, CDCl₃) δ 4.28(s, 4H); 6.92(d, J = 8.4 Hz,2H); 7.06(d, J = 8.0 Hz, 2H); 7.11(s, 2H); 7.13(d, J = 8.4 Hz, 2H);7.28(d, J = 7.6 Hz, 2H); 7.51(tr, J = 8.4 Hz, 2H); 7.87(s, 2H); 7.89(d,J = 8.4 Hz, 2H).

TABLE 13 Compound 32′ Yield and NMR spectrum data

Yield: 84%, ¹H NMR(400 MHz, CDCl₃) δ 4.19(s, 4H); 7.13(d, J = 8.4 Hz,2H); 7.32(tr, J = 7.6 Hz, 2H); 7.47(dd, J = 8.4 Hz, 2 Hz, 2H);7.53-7.58(m, 4H); 7.88(s, 2H); 7.92(d, J = 8.4 Hz, 2H).

Yield: 67%, ¹H NMR(400 MHz, CDCl₃) δ 4.48(s, 4H); 7.17(d, J = 8.4 Hz,2H); 7.31-7.43(m, 6H); 7.52-7.57 (m, 2H); 7.70(s, 2H); 7.85-7.90(m, 4H);7.94(d, J = 8.4 Hz, 2H); 8.19(s, 2H).

Yield: 89%, ¹H NMR(400 MHz, CDCl₃) δ 4.20(d, J = 10 Hz, 2H); 4.23(d, J =10 Hz, 2H); 6.87-6.93(m, 2H); 7.13-7.18(m, 6H); 7.32(tr, J = 8.0 Hz,2H); 7.54(tr, J = 8.0 Hz, 2H); 7.90(s, 2H); 7.92(d, J = 8.4 Hz, 2H).

Yield: 84%, ¹H NMR(400 MHz, CDCl₃) δ 3.87(s, 6H); 4.29(s, 4H);6.97-7.00(m, 2H); 7.15-7.21(m, 6H); 7.27-7.31(m, 2H); 7.39(tr, J = 8.4Hz, 2H); 7.49-7.53 (m, 2H); 7.91(d, J = 8.4 Hz, 2H); 7.92(s, 2H).

Yield: 81%, ¹H NMR(400 MHz, CDCl₃) δ 4.27(s, 4H); 6.90-6.93(m, 2H);7.10-7.17(m, 6H); 7.25-7.29(m, 2H); 7.34(tr, J = 8.0 Hz, 2H);7.48-7.52(m, 2H); 7.89(d, J = 8.0 Hz, 2H); 7.90(s, 2H).

TABLE 14 Compound 32′ Yield and NMR spectrum data

Yield: 80%, ¹H NMR(400 MHz, CDCl₃) δ 4.12(s, 4H); 7.10(d, J = 8.4 Hz,2H); 7.24-7.28(m, 2H); 7.48(tr, J = 7.2 Hz, 2H); 7.55(tr, J = 8.0 Hz,2H); 7.64(d, J = 8.0 Hz, 2H); 7.76(d, J = 8.0 Hz, 2H); 7.83-7.87(m, 6H).

Yield: 85%, ¹H NMR(400 MHz, CDCl₃) δ 4.22(s, 4H); 7.17(d, J = 8.0 Hz,2H); 7.31-7.35(m, 2H); 7.53-7.57(m, 2H), 7.76(tr, J = 6.4 Hz, 8H),7.91(s, 2H); 7.93(d, J = 8.0 Hz, 2H).

Not determined

Yield: 83%, ¹H NMR(400 MHz, CDCl₃) δ 3.16(s, 6H); 4.20(s, 4H); 7.17(d, J= 8.4 Hz, 2H); 7.33-7.37(m, 2H); 7.57(tr, J = 7.6 Hz, 2H); 7.85(d, J =8.4 Hz, 4H); 7.91(s, 2H); 7.95(d, J = 8.4 Hz, 2H); 8.09(d, J = 8.4 Hz,4H).

TABLE 15 Compound 32′ Yield and NMR spectrum data

not determined

Yield: 66%, ¹H NMR(400 MHz, CDCl₃) δ 4.35(s, 4H); 7.23(d, J = 8.8 Hz,2H); 7.33(tr, J = 7.6 Hz, 2H); 7.52-7.56(m, 6H); 7.76(d, J = 8.4 Hz,2H); 7.92-7.96(m, 8H); 7.99(d, J = 8.8 Hz, 2H); 8.10(s, 2H).

Not determined

Yield: 81%, ¹H NMR(400 MHz, CDCl₃) δ 4.32(d, J = 10.0 Hz, 2H); 3.56(d, J= 10.0 Hz, 2H); 7.24(d, J = 8.4 Hz, 2H); 7.37-7.41(m, 2H); 7.58-7.62(m,2H); 7.88(tr, J = 5.6 Hz, 2H); 7.94(s, 4H); 8.00(d, J = 1.6 Hz, 6H);8.06(s, 2H); 8.17(s, 8H).

Reference Example 17 Synthesis (2) of Starting Material (Compound 33′)for Synthesizing Quaternary Ammonium Salt

The same procedure as in Example 1 was performed except that thecompounds 32′ (S-form) obtained in Reference Example 6 were used anddibutylamine as used in Example 1 was used. The product were purified bysilica gel column chromatography to give compounds 33′ respectively ingood yields. The R-form can be prepared in the same procedure.

The specific structural formulae and the NMR spectrum data of theobtained compounds 33′ are shown in Tables 16 to 19.

TABLE 16 Compound 33′ Yield and NMR spectrum data

Yield: 81%, ¹H NMR(400 MHz, CDCl₃) δ 0.26(br, 2H); 0.82(tr, J = 7.2 Hz,6H); 0.84-1.64(m, 6H); 2.62(tr, J = 13.2 Hz, 2H); 3.12(d, J = 13.2 Hz,2H); 3.69(d, J = 14.0 Hz, 2H); 5.18(d, J = 14.0 Hz, 2H); 7.35-7.40(m,6H); 7.46(tr, J = 8.0 Hz, 4H); 7.63-7.69(m, 10H); 7.84(m, 4H); 8.05(d, J= 8.0 Hz, 2H); 8.14(s, 2H).

Yield: 52%, ¹H NMR(400 MHz, CDCl₃) δ 0.15-0.22(m, 2H); 0.60(tr, J = 7.2Hz, 6H); 0.87-1.01(m, 6H); 2.55-2.63(m, 2H); 3.25(tr, J = 13.2 Hz, 2H);3.80(d, J = 14.0 Hz, 2H); 5.05(d, J = 14.0 Hz, 2H); 7.37(d, J = 8.8 Hz,2H); 7.45(tr, J = 7.6 Hz, 2H); 7.70(tr, J = 7.6 Hz, 2H); 7.85(d, J = 8.8Hz, 2H); 8.08(d, J = 8.4 Hz, 2H); 8.12(s, 2H); 8.46(d, J = 8.4 Hz, 4H).

Yield: 78%, ¹H NMR(400 MHz, CDCl₃) δ 0.17-0.19(m, 2H), 0.66(tr, J = 7.2Hz, 6H); 0.84-0.87(m, 2H); 0.94-1.00(m, 4H); 2.52(tr, J = 8.4 Hz, 2H);3.23(tr, J = 12.4 Hz, 2H); 3.73(d, J = 14.4 Hz, 2H); 5.03(d, J = 14.4Hz, 2H); 7.34(d, J = 8.4 Hz, 2H); 7.40-7.44(m, 2H); 7.68(tr, J = 7.2 Hz,2H); 7.78(d, J = 8.0 Hz, 4H); 7.89(d, J = 8.0 Hz, 4H); 8.06(d, J = 8.0Hz, 2H); 8.09 (s, 2H).

Yield: 86%, ¹H NMR(400 MHz, CDCl₃) δ 0.42(b, 2H); 0.74(tr, J = 6.8 Hz,6H); 0.98-1.07(m, 6H); 2.60-2.63 (m, 2H); 3.16-3.18(m, 2H); 3.57-3.60(m,2H); 5.23-5.29(m, 2H); 6.05(d, J = 12.0 Hz, 4H); 7.04-7.06 (m, 6H);7.32-7.38(m, 4H); 7.62(d, J = 7.6 Hz, 2H); 8.00(tr, J = 8.0 Hz, 2H);8.04(s, 2H).

TABLE 17 Compound 33′ Yield and NMR spectrum data

Yield: 65%, ¹H NMR (400 MHz, CDCl₃) δ 0.23 (br, 2H); 0.69 (tr, J = 7.2Hz, 6H); 0.89-1.02 (m, 6H); 2.56 (br, 2H); 3.19 (br, 2H); 3.59-3.65 (m ,2H); 5.05 br, 2H); 7.28-7.41 (m, 4H); 7.54-7.70 (m, 8H); 8.25-8.11 (m,4H).

Yield: 76%, ¹H NMR (400 MHz, CDCl₃) δ 0.19 (tr, J = 7.2 Hz, 6H);0.79-0.96 (m, 8H); 2.73-2.74 (m, 2H); 3.22 (tr , J = 16.0 Hz, 2H); 3.70(d, J = 14.0 Hz, 2H); 5.60 (d, J = 14.0 Hz, 2H); 7.33-7.43 (m, 8H); 7.66(tr, J = 8.0 Hz, 2H); 7.86 (d, J = 7.6 Hz, 4H); 8.05(d, J = 8.4 Hz, 4H);8.30 (s, 2H).

Yield: 62%, ¹H NMR (400 MHz, CDCl₃) δ 0.32-0.34 (m, 2H); 0.71 (tr, J =7.2 Hz, 6H); 0.99-1.09 (m, 6H); 3.27 (tr, J = 12.8 Hz, 2H); 3.73 (d, J =14.4 Hz, 2H); 5.00(d, J = 14.4 Hz, 2H); 6.90 (tr, J = 8.8 Hz, 2H);7.05-7.23 (m, 4H); 7.23-7.39 (m, 4H); 7.62 (tr, J = 8.4 Hz, 2H); 8.02(d, J = 8.4 Hz, 2H); 8.04 (s, 2H).

Yield: 79%, ¹H NMR (400 MHz, CDCl₃) δ 0.20 (b, 2H); 0.65 (tr, J = 7.2Hz, 6H); 0.93-1.04 (m , 6H); 2.62-2.64 (tr, J = 13.2 Hz, 2H); 3.06 (tr,J = 13.2 Hz, 2H); 3.64 (m, 2H); 3.91 (s, 6H); 5.08 (m, 2H); 7.02 (d, J =8.0 Hz, 2H); 7.18-7.20 (m, 2H); 7.38 (d, J = 4 Hz, 4H); 7.49-7.50 (m,2H); 7.62-7.66 (m, 2H); 8.03 (d, J = 8.4 Hz, 2H); 8.08 (s, 2H).

Yield: 89%, ¹H NMR (400 MHz, CDCl₃) δ 0.27 (br, 2H); 0.62 (tr, J = 7.2Hz, 6H); 0.80-0.85 (br, 6H); 2.48 (br, 2H); 2.94 (br, 2H); 3.51 (br,2H); 5.30 (br, 2H); 6.92-6.99 (br, 4H); 7.24-7.32 (m, 8H); 7.52 (br,2H); 7.98 (d, J = 8.4 Hz, 2H); 8.04 (s, 2H); 8.47 (br, 2H).

TABLE 18 Compound 33′ Yield and NMR spectrum data

Yield: 62%, ¹H NMR (400 MHz, CDCl₃) δ 0.15 (b, 2H); 0.60 (tr, J = 7.2Hz, 6H); 0.72-0.98 (m, 6H); 2.59 (tr, J = 13.2 Hz, 2H); 3.15 (tr, J =13.2 Hz, 2H), 3.75 (d, J = 14.0 Hz, 2H); 5.04 (d, J = 14.0 Hz, 2H);7.36-7.44 (m, 4H); 7.67 (tr, J = 7.6 Hz, 2H); 7.77-7.79 (m, 4H); 7.87(d, J = 7.6 Hz, 4H); 8.03-8.13 (m, 4H).

Yield: 71%, ¹H NMR (400 MHz, CDCl₃) δ 0.15 (br, 2H); 0.61 (tr, J = 7.2Hz, 6H); 0.74-0.98 (m, 6H); 3.20 (tr, J = 12.8 Hz, 2H); 3.75 (d, J =14.0 Hz, 2H); 5.09 (d, J = 14.0 Hz, 2H); 7.36 (d, J = 8.4 Hz, 2H); 7.42(tr, J = 7.2 Hz, 2H); 7.68 (tr, J = 7.2 Hz, 2H); 7.78 (d, J = 8.0 Hz,4H): 7.88 (d, J = 8.0 Hz, 4H); 8.06 (d, J = 8.0 Hz, 2H).

Yield: 73% ¹H NMR (400 MHz, CDCl₃) δ 0.35 (br, 2H); 0.72 (tr, J = 7.2Hz, 6H); 0.89-1.08 (m, 6H); 2.65-2.69 (m, 2H); 3.20 (tr, J = 12.8 Hz,2H); 3.75 (d, J = 14.0 Hz, 2H); 4.97 (d, J = 14.0 Hz, 2H); 6.91-6.99 (m,2H); 7.16 (br, 4H); 7.32-7.41 (m, 4H); 7.64 (tr, J = 7.6 Hz, 2H); 8.03(d, J = 8.0 Hz, 2H); 8.11 (d, J = 8.0 Hz, 2H).

Yield: 75%, ¹H NMR (400 MHz, CDCl₃) δ 0.24 (br, 2H); 0.88 (tr, J = 7.2Hz, 6H); 1.24-1.43 (m, 6H); 2.56 (tr, J = 13.2 Hz, 2H); 3.28 (tr, J =13.2 Hz, 2H); 3.72 (d, J = 14.0 Hz, 2H); 4.97 (d, J = 14.0 Hz, 2H); 7.39(d, J = 8.4 Hz, 2H); 7.46 (tr, J = 7.6 Hz, 2H); 7.70 (tr, J = 7.6 Hz,2H); 7.79 (br, 4H); 8.08 (d, J = 8.4 Hz, 2H); 8.11 (s, 2H); 8.20 (d, J =8.4 Hz, 4H).

TABLE 19 Compound 33′ Yield and NMR spectrum data

Yield: 61%, ¹H NMR (400 MHz, CDCl₃) δ 0.39-0.41 (m, 2H); 0.49 (tr; J =7.2 Hz, 6H); 0.90-1.01 (m, 6H); 2.75-2.80 (m, 2H); 3.29 (tr, J = 12.8Hz, 2H); 3.89 (d, J = 14.0 Hz, 2H); 5.09 (d, J = 14.0 Hz, 2H); 7.35-7.47(m, 12H); 7.63(s, 2H); 7.67-7.70 (m, 2H); 7.78 (d, J = 8.8 Hz, 2H); 8.00(s, 2H); 8.08 (d, J = 8.0 Hz, 2H); 8.15 (s, 2H).

Yield: 74%, ¹H NMR (400 MHz, CDCl₃) δ −0.21 (br, 4H); 0.46-0.96 (m,10H); 2.62 (tr; J = 13.2 Hz, 2H); 3.00 (tr, J = 13.2 Hz, 2H); 7.75 (d, J= 14.0 Hz, 2H); 5.08 (br, 2H); 7.38-7.42 (m, 4H); 7.53-7.59 (m, 4H);7.65-7.69 (m, 4H); 7.92 (d, J = 6.8 Hz, 4H); 8.07-8.09 (m, 6H); 8.21 (s,2H).

Yield: 45%, ¹H NMR (400 MHz, CDCl₃) δ 0.42 (b, 2H); 0.71 (tr, J = 7.2Hz, 6H); 2.62-2.69 (m, 2H); 3.87-3.91 (m, 2H); 4.27 (d, J = 14.0 Hz,2H); 5.28 (d, J = 14.0 Hz, 2H); 7.22 (d, J = 8.4 Hz, 2H); 7.37-7.42 (m,6H); 7.55 (tr, J = 7.6 Hz, 2H); 7.64-7.67 (m, 2H); 7.76 (tr, J = 7.6 Hz,2H); 8.07 (d, J = 8.4 Hz, 2H); 8.16 (s, 2H).

Yield: 93%, ¹H NMR (400 MHz, CDCl₃) δ 0.52 (tr, J = 7.2 Hz, 6H);0.81-0.94 (m, 8H); 2.82 (tr, J = 13.6 Hz, 2H); 3.31 (tr, 13.6 Hz, 2H);3.94 (d, J = 14.0 Hz, 2H); 5.07 (d, J = 14.0 Hz, 2H); 7.47 (d, J = 3.6Hz, 4H); 7.69-7.74 (m, 2H); 7.75 (s, 2H); 7.91(d, J = 3.6 Hz, 2H); 7.92(d, J = 1.6 Hz, 2H); 8.05 (s, 2H); 8.12 (s, 2H); 8.14-8.17 (m, 8H); 8.20(s, 2H).

Example 18 Examination (1) of Effect of Substituent of Phase-TransferCatalyst

According to Example 11, α-benzylation was performed at 0° C., using 3mol % of phase-transfer catalysts described Tables 20 to 22 below. Theresults are shown in Tables 20 to 22.

TABLE 20 Phase-transfer catalyst:

Reaction time Yield Optical purity Ar Ar′ (hr) (%) (% ee)

1.5 65 65

1.5 88 87

2 65 80

24 86 58

1 70 64

4 87 66

TABLE 21 Phase-transfer catalyst:

Reaction time Yield Optical purity Ar (hr) (%) (% ee)

7 92 82

7 93 83

2 97 77

4 94 75

21 86 97

3 62 93

5 97 91

3 85 71

3 89 89

TABLE 22 Phase-transfer catalyst:

    Reaction time (hr)     Yield (%)     Optical purity (% ee)

7 98 93

1 78 81

2 55 78

Example 19 Examination (2) of Effect of Substituent of Phase-TransferCatalyst

According to Example 11, α-benzylation was performed at 0° C., using 3mol % of phase-transfer catalysts described Tables 23 to 26 below. Theresults are shown in Tables 23 to 26.

TABLE 23 Reaction Optical time Yield purity Phase-transfer catalyst (hr)(%) (% ee)

3 78 68.7

3 88.7 92.2

3 91 93.8

3 86 74.5

TABLE 24 Reaction Optical time Yield purity Phase-transfer catalyst (hr)(%) (% ee)

3 91 86.9

3 71 90

3 94 92.8

3 52 73.4

3 85 77.8

TABLE 25 Reaction Optical time Yield purity Phase-transfer catalyst (hr)(%) (% ee)

3 89 82.8

3 89 90.5

3 89.8 91

3 83 90

TABLE 26 Reaction time Yield Optical purity Phase-transfer catalyst (hr)(%) (% ee)

3 76.5 81.05

3 60 77.2

3 92 61.6

3 77 81.4

Example 20 Examination of Effect of Stirring

According to Example 11, benzylation was performed at 0° C. for onehour, by using 3 mol % of the compound 16 (S-form) as a phase-transfercatalyst under stirring with a stronger stirrer. In spite of only onehour reaction, the yield based on the HPLC analysis of the reactionmixture was 78% and after purification on a silica gel column the yieldwas 72%, and the optical purity was 99% ee. The reaction time is muchshorter and the yields are higher than the results shown in Table 1,which indicates that stronger stirring provides much better reactionefficiency.

Example 21 Benzylation (1) of Alanine

To a mixture of alanine tert-butyl ester-p-chlorobenzyl Schiff base(compound 8) (134 mg, 0.5 mmol), phase-transfer catalysts described inTable 27 below (3 mol %), and benzyl bromide (1.2 equivalents) in 2 mLof toluene, cesium hydroxide.monohydrate (5 equivalents) was added at 0°C., and the mixture was stirred under an air atmosphere at 0° C. for 30min (first process). The reaction mixture was poured into water andextracted with dichloromethane, and the solvent was removed, and theresidue was dissolved in 5 mL of tetrahydrofuran. Then, 5 mL of 0.5 Mcitric acid aqueous solution was added thereto and the mixture wasstirred at room temperature for one hour (second process). The aqueouslayer was washed with ether and alkalized with sodium hydrogencarbonate,and then extracted with dichloromethane. The organic layer was driedover sodium sulfate and concentrated to give an oily product. Theobtained oily product was subjected to silica gel column chromatography(eluent: ethyl acetate/hexane=2/1) to give a benzylated product ofalanine (compound 9). The optical purity of the obtained product wasanalyzed by HPLC [Daicel Chiralcel AD; eluent: hexane/isopropanol=30:1,0.5 mL/min; retention time: (R)-form=12.9 min, (S)-form=20.5 min]. Theyield and the optical purity are shown in Table 27.

TABLE 27 Optical Yield purity Phase-transfer catalyst (%) (% ee)

58 63

76 97

65 54

65 95

72 82

72 49

71 80

65 95

70 61

70 94

Example 22 Benzylation (2) of Alanine

Alanine was benzylated in the same manner as in Example 21, except thatthe phase-transfer catalyst was used in 1 mol %, the phase-transfercatalysts described in Table 28 below were used, and the reactioncondition was changed to −20° C. under an argon atmosphere in the firstprocess. The results are shown in Table 28.

TABLE 28 Optical Yield purity Phase-transfer catalyst (%) (% ee)

78 85

85 99

76 73

78 98

71 67

85 92

Example 23 Allylation of Phenylalanine

To a mixture of phenylalanine tert-butyl ester-p-chlorobenzyl Schiffbase (compound 34) (172 mg, 0.5 mmol), phase-transfer catalystsdescribed in Table 29 below (1 mol %), and allyl bromide (1.2equivalents) in 2 mL of toluene, cesium hydroxide.monohydrate (5equivalents) was added at 0° C., and the mixture was stirred under anargon atmosphere at −20° C. for 30 min (first process). The reactionmixture was poured into water and extracted with dichloromethane, andthe solvent was removed, and the residue was dissolved in 5 mL oftetrahydrofuran. Then, 5 mL of 0.5 M citric acid aqueous solution wasadded thereto and stirred at room temperature for one hour (secondprocess). The aqueous layer was washed with ether and alkalized withsodium hydrogencarbonate, and then extracted with dichloromethane. Theorganic layer was dried over sodium sulfate and concentrated to give anoily product. The obtained oily product was subjected to silica gelcolumn chromatography (eluent: ethyl acetate/hexane=½) to give anallylated product of phenylalanine (compound 35). The optical purity ofthe obtained product was analyzed by HPLC [Daicel Chiralpak AD; eluenthexane/isopropanol=100:1, 0.5 mL/min; retention time: (R)-form=14.9 min,(S)-form=20.2 min]. The results are shown in Table 29.

TABLE 29 Optical Yield purity Phase-transfer catalyst (%) (% ee)

65 70

76 97

76 74

79 95

72 96

Example 24 Cinnamylation of Phenylalanine

A cinnamylated product of phenylalanine (compound 36) was obtained inthe same manner as in Example 23, except that cinnamyl bromide was usedinstead of allyl bromide and the compound 7 was used as thephase-transfer catalyst in the first process. The optical purity of theobtained product was analyzed by HPLC. The yield was 69%, and theoptical purity was 92% ee.

Example 25 Propargylation of Phenylalanine

A propargylated product of phenylalanine (compound 37) was obtained inthe same manner as in Example 23, except that propargyl bromide was usedinstead of allyl bromide in the first process. The optical purity of theobtained product was analyzed by HPLC. The results are shown in Table30.

TABLE 30 Optical Yield purity Phase-transfer catalyst (%) (% ee)

79 63

61 94

67 62

77 91

77 92

Example 26 Tert-Butoxycarbonylmethylation of Phenylalanine

A compound 38 was obtained in the same manner as in Example 23, exceptthat α-bromoacetic acid tert-butyl ester was used instead of allylbromide and the compound 7 was used as the phase-transfer catalyst inthe first process. The optical purity of the obtained product wasanalyzed by HPLC. The yield was 66%, and the optical purity was 94% ee.

Example 27 Examination of Catalyst Formation and Benzylation in OneVessel

The compound 39 (S-form) described in Table 31 below (3 mol %),secondary amine described in Table 10 below (6 mol %) and potassiumcarbonate (4.5 mol %) were mixed in dioxane (5 mL), and stirred for 10hours with heating and reflux. Then, to this reaction mixture, glycinetert-butyl ester benzophenone Schiff base (compound 20) (1 equivalent,0.5 mmol), 50% potassium hydroxide aqueous solution (1.0 mL), andtoluene (3.0 mL) were added, and benzyl bromide (1.2 equivalents) wasadded dropwise at 0° C. After stirring at 0° C. respectively for aperiod as described in Table 31 below, the reaction mixture was pouredinto water, and extracted with ether. The ether extract was washed withsaturated brine, dried over sodium sulfate and concentrated underreduced pressure. The oily residue was subjected to silica gel columnchromatography (eluted with ether/hexane= 1/10) to give(S)-phenylalanine tert-butyl ester benzophenone Schiff base (compound21). The optical purity of the obtained product was analyzed by HPLC[Daicel Chiralcel OD; eluent: hexane/2-propanol=100:1, 0.5 mL/min;retention time: (R)-form=14.8 min, (S)-form=28.2 min]. The results areshown all together in Table 31.

TABLE 31 Secondary amine R = H R = Ph R = 3,5-(CF₃)₂Ph R = 3,4,5-F₃Ph(CH₃)₂NH 12% ee (66%, 58 hr) 26% ee (68%, 5 days) 1% ee (57%, 30 hr) 7%ee (44%, 4 days) (C₄H₉)₂NH −27% ee (53%, 72 hr) 43% ee (89%, 54 hr) 70%ee (85%, 48 hr) 97% ee (76%, 24 hr) (C₁₀H₂₁)₂NH −17% ee (76%, 90 hr) 58%ee (86%, 24 hr) 96% ee (96%, 24 hr) 97% ee (86%, 72 hr) (iso-C₄H₉)₂NH−9% ee (52%, 72 hr) 22% ee (14%, 5 days) 44% ee (34%, 24 hr) 7% ee (65%,4 days)

1% ee (59%, 72 hr) 41% ee (86%, 36 hr) 75% ee (50%, 4 days) 83% ee (98%,6 hr)

−19% ee (83%, 36 hr) −57% ee (71%, 4 days) 78% ee (33%, 29 hr) 81% ee(83%, 24 hr)

22% ee (44%, 51 hr) 3% ee (72%, 4 days) 2% ee (10%, 7 days) 6% ee (13%,6 days)

−7% ee (56%, 4 days) 5% ee (78%, 24 hr) 31% ee (24%, 4 days) 43% ee(80%, 24 hr)

−23% ee (67%, 48 hr) 33% ee (82%, 12 hr) 41% ee (3%, 8 days) 20% ee(72%, 48 hr)

−8% ee (54%, 24 hr) n.t. n.t. 8% ee (23%, 7 days)

n.t. n.t. n.t. 10% ee (13%, 6 hr) The values in the table show theoptical purity (% ee). The parenthesized values in the table show theyield (%) and the reaction time. In the optical purity, the values with− show that a product having the opposite configuration was obtained.The n.t. shows that no experiment was performed.

Thus, it was found that the phase-transfer catalyst can be used foralkylation of α-amino acid derivatives without isolation.

Example 28 α-Benzylation (1) in which the Amount of the Phase-TransferCatalyst Used is Reduced

Glycine tert-butyl ester benzophenone Schiff base (compound 20) (88.6mg, 0.3 mmol), the phase-transfer catalyst (compound 7) obtained inExample 1 in 0.05 mol % to the compound 20, 50% potassium hydroxideaqueous solution (1.0 mL), and toluene (3.0 mL) were mixed, and benzylbromide (43 μg, 0.36 mmol) was added dropwise at 0° C. After stirringvigorously at 0° C. over 4 hours, the reaction mixture was poured intowater, and extracted with ether. The ether extract was washed withsaturated brine, dried over sodium sulfate and concentrated underreduced pressure. The oily residue was subjected to silica gel columnchromatography (eluted with ether/hexane= 1/10) to give(R)-phenylalanine tert-butyl ester benzophenone Schiff base (compound21). The optical purity of the obtained product was analyzed by HPLC[Daicel Chiralcel OD; eluent hexane/2-propanol=100:1, flow rate: 0.5mL/min; retention time: (R)-form=14.8 min, (S)-form=28.2 min].

The yield and the optical purity of the obtained compound 21 are shownin Table 32.

Example 29 α-Benzylation (2) in which the Amount of the Phase-TransferCatalyst Used is Reduced

(R)-Phenylalanine tert-butyl ester benzophenone Schiff base (compound21) was obtained by performing a reaction in the same manner as inExample 28, except that the amount of the phase-transfer catalyst(compound 7) obtained in Example 1 was 0.01 mol % to the compound 20,and that the reaction time was 26 hours. The yield and the opticalpurity of the obtained compound 21 are shown in Table 32.

Example 30 α-Benzylation (3) in which the Amount of the Phase-TransferCatalyst Used is Reduced

(R)-Phenylalanine tert-butyl ester benzophenone Schiff base (compound21) was obtained by performing a reaction in the same manner as inExample 28, except that the amount of the phase-transfer catalyst(compound 7) obtained in Example 1 was 0.005 mol % to the compound 20,and that the reaction time was 26 hours. The yield and the opticalpurity of the obtained compound 21 are shown in Table 32.

Example 31 α-Benzylation (4) in which the Amount of the Phase-TransferCatalyst Used is Reduced

(R)-Phenylalanine tert-butyl ester benzophenone Schiff base (compound21) was obtained by performing a reaction in the same manner as inExample 28, except that, in addition to the phase-transfer catalyst(compound 7) obtained in Example 1, tetrabutyl ammonium bromide (TBAB)in 0.05 mol % to the compound 20 was added as cocatalyst, and that thereaction time was 1.5 hours. The yield and the optical purity of theobtained compound 21 are shown in Table 32.

Example 32 α-Benzylation (5) in which the Amount of the Phase-TransferCatalyst Used is Reduced

(R)-Phenylalanine tert-butyl ester benzophenone Schiff base (compound21) was obtained by performing a reaction in the same manner as inExample 28, except that, in addition to the phase-transfer catalyst(compound 7) obtained in Example 1, tetrabutyl ammonium bromide (TBAB)in 0.025 mol % to the compound 20 was added as cocatalyst, and that thereaction time was 1.5 hours. The yield and the optical purity of theobtained compound 21 are shown in Table 32.

Example 33 α-Benzylation (6) in which the Amount of the Phase-TransferCatalyst Used is Reduced

(R)-Phenylalanine tert-butyl ester benzophenone Schiff base (compound21) was obtained by performing a reaction in the same manner as inExample 28, except that, in addition to the phase-transfer catalyst(compound 7) obtained in Example 1, tetrabutyl ammonium bromide (TBAB)in 0.0167 mol % to the compound 20 was added as cocatalyst, and that thereaction time was 2 hours. The yield and the optical purity of theobtained compound 21 are shown in Table 32.

TABLE 32 Amount of the Optical phase-transfer Amount of Reaction Yieldof purity of catalyst obtained in TBAB time compound 21 compound 21Example 1 (mol %) *1 (mol %) *1 (hr) (%) (% ee) Example 28 0.05 no 4 8799 Example 29 0.01 no 26 41 97 Example 30 0.005 no 26 29 94 Example 310.05 0.05 1.5 99 94 Example 32 0.05 0.025 1.5 91 95 Example 33 0.050.0167 2 91 96 *1 Based on the amount of compound 20

As shown in Table 32, according to the methods described in Examples 28to 33, (R)-phenylalanine tert-butyl ester benzophenone Schiff base(compound 21) can be produced in an even better optical purity.Furthermore, when TBAB is used in combination as a cocatalyst (Examples31 to 33), the yield of the optically active compound 21 can beimproved, and the reaction time up to achieving this can be also reducedat the same time.

Example 34 Hydrolysis (1) of Tert-Butyl Ester

To the benzylated product (compound 9) obtained by either one of Example2, 21 or 22, a 5N potassium hydroxide aqueous solution (an excessiveamount with respect to the compound 9) is added, and the mixture isstirred for one hour until the solution becomes uniform on a water bathat 40° C. to 50° C. After cooling to room temperature, 2N hydrochloricacid is added until the pH reaches 6.0. After confirming the productionof precipitate, the solution is stirred under ice cooling for 30 min.The precipitate is filtered and washed with ethanol (appropriateamount). The crystals are dried at 50° C. overnight to give the compound40 in a good yield and optical purity.

Example 35 Hydrolysis (2) of Tert-Butyl Ester

The compound 41 is obtained in a good yield and optical purity in thesame manner as in Example 34, except that the allylated product(compound 35) obtained in Example 23 is used instead of the benzylatedproduct (compound 9) obtained by either one of Example 2, 21 or 22.

Example 36 Hydrolysis (3) of Tert-Butyl Ester

The compound 42 is obtained in a good yield and optical purity in thesame manner as in Example 34, except that the cinnamylated product(compound 36) obtained in Example 24 is used instead of the benzylatedproduct (compound 9) obtained by either one of Example 2, 21 or 22.

Example 37 Hydrolysis (4) of Tert-Butyl Ester

The compound 43 is obtained in a good yield and optical purity in thesame manner as in Example 34, except that the propargylated product(compound 37) obtained in Example 25 is used instead of the benzylatedproduct (compound 9) obtained by either one of Example 2, 21 or 22.

Example 38 Hydrolysis (5) of Tert-Butyl Ester

The compound 44 is obtained in a good yield and optical purity in thesame manner as in Example 34, except that thetert-butoxycarbonylmethylated product (compound 38) obtained in Example26 is used instead of the benzylated product (compound 9) obtained byeither one of Example 2, 21 or 22.

INDUSTRIAL APPLICABILITY

The present invention provides a chiral phase-transfer catalyst having asimpler configuration. This phase-transfer catalyst can be produced by afewer number of processes than for a conventional compound, whichreduces the cost. Such a phase-transfer catalyst is very useful forsynthesis of α-alkyl-α-amino acid and derivatives thereof andα,α-dialkyl-α-amino acid and derivatives thereof. The amino acid andderivatives thereof play a special role in the design of a peptidehaving enhanced characteristics as an effective enzyme inhibitor and asa chiral structure block for synthesis of compounds having variousbiological activities. Therefore, the present invention is useful fordevelopment of novel foods or pharmaceuticals.

What is claimed is:
 1. A method for producing an optically active α-amino acid, comprising: alkylating a compound represented by the formula (IV):

with a compound of the formula (V): R¹⁸—W  (V) to give a compound represented by the formula (VI):

using a compound represented by the formula (I) that is pure with respect to axis symmetry as a phase-transfer catalyst:

in a medium in the presence of an inorganic base, wherein in the formula (I), R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are groups independently selected from the group consisting of: (i) a hydrogen atom; (ii) —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group); (iii) a cyano group; (iv) a nitro group; (v) a carbamoyl group; (vi) an N—(C₁ to C₄ alkyl)carbamoyl group; (vii) an N,N-di(C₁ to C₄ alkyl)carbamoyl group; (viii) —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched); (ix) a C₁ to C₆ alkyl group that may be branched or form a cyclic group; (x) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (xi) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (xii) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (xiii) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (xiv) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a halogen atom, and —S—R, —SO—R, or —SO₂—R (where R is a C₁ to C₄ alkyl group that may be branched); or may be substituted with —O—CH₂—O— or —O—(CH₂)₂—O— at positions 3 and 4 taken together; and (xv) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and R⁷ and R⁸ are groups independently selected from the group consisting of: (i) a hydrogen atom; (ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclic group; (iii) a C₂ to C₁₂ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₁₂ alkynyl group that may be branched or form a cyclic group; (vii) —(CH₂)_(n)OCONR¹⁰R¹¹ (where R¹⁰ and R¹¹ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (4) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (5) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (6) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (7) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (8) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (viii) —(CH₂)_(n)CONR¹²R¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (ix) —(CH₂)_(n)NR¹²COR¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (x) —(CH₂)_(n)NR¹²R¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xi) —(CH₂)_(n)Y—OR¹² (where Y is a C₁ to C₄ divalent saturated hydrocarbon group that may be branched, and R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xiii) —(CH₂)_(n)—S—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xiv) —(CH₂)_(n)—SO—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); and (xv) —(CH₂)_(n)—SO₂—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); or R⁷ and R⁸ are taken together to form a divalent group selected from the group consisting of: —(CH₂)_(m)— (where m is an integer from 2 to 8);

wherein X⁻ is an anion selected from the group consisting of a halide anion, SCN⁻, HSO₄ ⁻ and HF₂ ⁻, provided that in a case where R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are all hydrogen atoms and X− is a halide anion, R⁷ and R⁸ are not both methyl groups, a combination of a methyl group and an n-butyl group, a combination of a methyl group and an isopropyl group, or a combination of an allyl group and a hydrogen atom, or R⁷ and R⁸ are not taken together to form —(CH₂)₄—, —(CH₂)₅— or

further provided that in a case where R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are all hydrogen atoms and X⁻ is a bromide ion or an iodide ion, R⁷ and R⁸ are not both cyclohexyl groups or allyl groups, in the formulae (IV) and (VI), R¹⁴ and R¹⁵ are each independently (i) a hydrogen atom; or (ii) an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, or a halogen atom; with the proviso the case where both R¹⁴ and R¹⁵ are hydrogen atoms is excluded, R¹⁶ is a group selected from the group consisting of: (i) a hydrogen atom; (ii) a C₁ to C₁₀ alkyl group that may be branched or form a cyclic group; (iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (v) an aralkyl group, wherein the aryl group of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vi) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vii) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (viii) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; R¹⁷ is a C₁ to C₈ alkyl group that may be branched or form a cyclic group), in the formulae (V) and (VI), R¹⁸ is a group selected from the group consisting of: (i) a C₁ to C₁₀ alkyl group that may be branched or form a cyclic group; (ii) a C₃ to C₉ alkyl group or substituted allyl group that may be branched or form a cyclic group; (iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (v) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of; a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vi) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vii) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of; a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (viii) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (ix) a C₃ to C₉ propargyl group or substituted propargyl group that may be branched, and in the formula (V), W is a functional group having a leaving ability, and in the formula (VI), * shows a newly produced asymmetric center; and hydrolyzing an imino group (R¹⁴R¹⁵C═N—) and an ester group (—CO₂R¹⁷) of the compound represented by the formula (VI):

under an acidic condition.
 2. The method of claim 1, wherein the compound represented by the formula (I) is used in a ratio of 0.001 mol % to 0.1 mol % per 1 mol of the compound represented by the formula (IV).
 3. The method of claim 1, wherein the compound represented by the formula (I) is used in a ratio of 0.005 mol % to 0.05 mol % per 1 mol of the compound represented by the formula (IV).
 4. A method for producing an optically active α-amino acid, comprising: alkylating a compound represented by the formula (IV):

with a compound of the formula (V): R¹⁸—W  (V) to give a compound represented by the formula (VI):

using a compound represented by the formula (I) that is pure with respect to axis symmetry as a phase-transfer catalyst:

in a medium in the presence of an inorganic base, wherein wherein in the formula (I), R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are groups independently selected from the group consisting of: (i) a hydrogen atom; (ii) —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group); (iii) a cyano group; (iv) a nitro group; (v) a carbamoyl group; (vi) an N—(C₁ to C₄ alkyl)carbamoyl group; (vii) an N,N-di(C₁ to C₄ alkyl)carbamoyl group; (viii) —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched); (ix) a C₁ to C₆ alkyl group that may be branched or form a cyclic group; (x) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (xi) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (xii) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (xiii) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (xiv) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a halogen atom, and —S—R, —SO—R, or —SO₂—R (where R is a C₁ to C₄ alkyl group that may be branched); or may be substituted with —O—CH₂—O— or —O—(CH₂)₂—O— at positions 3 and 4 taken together; and (xv) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and R⁷ and R⁸ are groups independently selected from the group consisting of: (i) a hydrogen atom; (ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclic group; (iii) a C₂ to C₁₂ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₁₂ alkynyl group that may be branched or form a cyclic group; (vii) —(CH₂)_(n)OCONR¹⁰R¹¹ (where R¹⁰ and R¹¹ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (4) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (5) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (6) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (7) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (8) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (viii) —(CH₂)_(n)CONR¹²R¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (ix) —(CH₂)_(n)NR¹²COR¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (x) —(CH₂)_(n)NR¹²R¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xi) —(CH₂)_(n)Y—OR¹² (where Y is a C₁ to C₄ divalent saturated hydrocarbon group that may be branched, and R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xiii) —(CH₂)_(n)—S—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xiv) —(CH₂)_(n)—SO—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); and (xv) —(CH₂)_(n)—SO₂—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); or R⁷ and R⁸ are taken together to form a divalent group selected from the group consisting of: —(CH₂)_(m)— (where m is an integer from 2 to 8);

wherein X⁻ is an anion selected from the group consisting of a halide anion, SCN⁻, HSO₄ ⁻ and HF₂ ⁻, provided that in a case where R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are all hydrogen atoms and X− is a halide anion, R⁷ and R⁸ are not both methyl groups, a combination of a methyl group and an n-butyl group, a combination of a methyl group and an isopropyl group, or a combination of an allyl group and a hydrogen atom, or R⁷ and R⁸ are not taken together to form —(CH₂)₄—, —(CH₂)₅— or

further provided that in a case where R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are all hydrogen atoms and X⁻ is a bromide ion or an iodide ion, R⁷ and R⁸ are not both cyclohexyl groups or allyl groups, in the formulae (IV) and (VI), R¹⁴ and R¹⁵ are each independently (i) a hydrogen atom; or (ii) an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, or a halogen atom; with the proviso the case where both R¹⁴ and R¹⁵ are hydrogen atoms is excluded, R¹⁶ is a group selected from the group consisting of: (i) a hydrogen atom; (ii) a C₁ to C₁₀ alkyl group that may be branched or form a cyclic group; (iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (v) an aralkyl group, wherein the aryl group of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vi) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vii) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (viii) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; R¹⁷ is a C₁ to C₈ alkyl group that may be branched or form a cyclic group), in the formulae (V) and (VI), R¹⁸ is a group selected from the group consisting of: (i) a C₁ to C₁₀ alkyl group that may be branched or form a cyclic group; (ii) a C₃ to C₉ allyl group or substituted allyl group that may be branched or form a cyclic group; (iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (v) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of; a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vi) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vii) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of; a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (viii) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (ix) a C₃ to C₉ propargyl group or substituted propargyl group that may be branched, and in the formula (V), W is a functional group having a leaving ability, and in the formula (VI), * shows a newly produced asymmetric center; and hydrolyzing an imino group (R¹⁴R¹⁵C═N—) of the compound represented by the formula (VI):

under an acidic condition; and hydrolyzing an ester group (—CO₂R¹⁷) of the acid hydrolyzed product under an acidic or basic condition.
 5. The method of claim 4, wherein the compound represented by the formula (I) is used in a ratio of 0.001 mol % to 0.1 mol % per 1 mol of the compound represented by the formula (IV).
 6. The method of claim 4, wherein the compound represented by the formula (I) is used in a ratio of 0.005 mol % to 0.05 mol % per 1 mol of the compound represented by the formula (IV).
 7. A method for producing an optically active α-amino acid, comprising: alkylating a compound represented by the formula (IV):

with a compound of the formula (V): R¹⁸—W  (V) to give a compound represented by the formula (VI):

using a compound represented by the formula (I) that is pure with respect to axis symmetry as a phase-transfer catalyst:

in a medium in the presence of an inorganic base, wherein wherein in the formula (I), R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are groups independently selected from the group consisting of: (i) a hydrogen atom; (ii) —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group); (iii) a cyano group; (iv) a nitro group; (v) a carbamoyl group; (vi) an N—(C₁ to C₄ alkyl)carbamoyl group; (vii) an N,N-di(C₁ to C₄ alkyl)carbamoyl group; (viii) —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched); (ix) a C₁ to C₆ alkyl group that may be branched or form a cyclic group; (x) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (xi) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (xii) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (xiii) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (xiv) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a halogen atom, and —S—R, —SO—R, or —SO₂—R (where R is a C₁ to C₄ alkyl group that may be branched); or may be substituted with —O—CH₂—O— or —O—(CH₂)₂—O— at positions 3 and 4 taken together; and (xv) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and R⁷ and R⁸ are groups independently selected from the group consisting of: (i) a hydrogen atom; (ii) a C₁ to C₁₂ alkyl group that may be branched or form a cyclic group; (iii) a C₂ to C₁₂ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₁₂ alkynyl group that may be branched or form a cyclic group; (vii) —(CH₂)_(n)OCONR¹⁰R¹¹ (where R¹⁰ and R¹¹ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (4) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (5) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (6) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (7) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (8) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (viii) —(CH₂)_(n)CONR¹²R¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (ix) —(CH₂)_(n)NR¹²COR¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (x) —(CH₂)_(n)NR¹²R¹³ (where R¹² and R¹³ are groups independently selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xi) —(CH₂)_(n)Y—OR¹² (where Y is a C₁ to C₄ divalent saturated hydrocarbon group that may be branched, and R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xii) —(CH₂)_(n)—OR¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xiii) —(CH₂)_(n)—S—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); (xiv) —(CH₂)_(n)—SO—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); and (xv) —(CH₂)_(n)—SO₂—R¹² (where R¹² is a group selected from the group consisting of: (1) a hydrogen atom; (2) a C₁ to C₄ alkyl group that may be branched; (3) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (4) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and n is an integer from 1 to 12); or R⁷ and R⁸ are taken together to form a divalent group selected from the group consisting of: —(CH₂)_(m)— (where m is an integer from 2 to 8);

wherein X⁻ is an anion selected from the group consisting of a halide anion, SCN⁻, HSO₄ ⁻ and HF₂ ⁻, provided that in a case where R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are all hydrogen atoms and X− is a halide anion, R⁷ and R⁸ are not both methyl groups, a combination of a methyl group and an n-butyl group, a combination of a methyl group and an isopropyl group, or a combination of an allyl group and a hydrogen atom, or R⁷ and R⁸ are not taken together to form —(CH₂)₄—, —(CH₂)₅— or

further provided that in a case where R¹, R^(1′), R², R^(2′), R³, R^(3′), R⁴, R^(4′), R⁵, R^(5′), R⁶, and R^(6′) are all hydrogen atoms and X⁻ is a bromide ion or an iodide ion, R⁷ and R⁸ are not both cyclohexyl groups or allyl groups, in the formulae (IV) and (VI), R¹⁴ and R¹⁵ are each independently (i) a hydrogen atom; or (ii) an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, or a halogen atom; with the proviso the case where both R¹⁴ and R¹⁵ are hydrogen atoms is excluded, R¹⁶ is a group selected from the group consisting of: (i) a hydrogen atom; (ii) a C₁ to C₁₀ alkyl group that may be branched or form a cyclic group; (iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (v) an aralkyl group, wherein the aryl group of the aralkyl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vi) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vii) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (viii) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; R¹⁷ is a C₁ to C₈ alkyl group that may be branched or form a cyclic group), in the formulae (V) and (VI), R¹⁸ is a group selected from the group consisting of: (i) a C₁ to C₁₀ alkyl group that may be branched or form a cyclic group; (ii) a C₃ to C₉ allyl group or substituted allyl group that may be branched or form a cyclic group; (iii) a C₂ to C₆ alkenyl group that may be branched or form a cyclic group; (iv) a C₂ to C₆ alkynyl group that may be branched or form a cyclic group; (v) an aralkyl group, wherein the aryl moiety of the aralkyl group may be substituted with at least one group selected from the group consisting of; a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vi) a heteroaralkyl group having a heteroaryl moiety, wherein the heteroaryl moiety may be substituted with at least one group selected from the group a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (vii) an aryl group, wherein the aryl group may be substituted with at least one group selected from the group consisting of; a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; (viii) a heteroaryl group, wherein the heteroaryl group may be substituted with at least one group selected from the group consisting of: a C₁ to C₄ alkyl group that may be branched, a C₁ to C₅ alkoxy group that may be branched, an aryl group that may be substituted with a C₁ to C₄ alkyl group that may be branched, a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, or —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), a cyano group, —NR²⁰R²¹ (where R²⁰ and R²¹ are each independently a hydrogen atom or a C₁ to C₄ alkyl group), a nitro group, a carbamoyl group, an N—(C₁ to C₄ alkyl)carbamoyl group, an N,N-di(C₁ to C₄ alkyl)carbamoyl group, —NHCOR⁹ (where R⁹ is a C₁ to C₄ alkyl group that may be branched), and a halogen atom; and (ix) a C₃ to C₉ propargyl group or substituted propargyl group that may be branched, and in the formula (V), W is a functional group having a leaving ability, and in the formula (VI), * shows a newly produced asymmetric center; and hydrolyzing an ester group (—CO₂R¹⁷) of the compound represented by the formula (VI):

under a basic condition; and hydrolyzing an imino group (R¹⁴R¹⁵C═N—) of the basic hydrolyzed product under an acidic condition.
 8. The method of claim 7, wherein the compound represented by the formula (I) is used in a ratio of 0.001 mol % to 0.1 mol % per 1 mol of the compound represented by the formula (IV).
 9. The method of claim 7, wherein the compound represented by the formula (I) is used in a ratio of 0.005 mol % to 0.05 mol % per 1 mol of the compound represented by the formula (IV). 